Method and apparatus for multi-antenna transmission in uplink

ABSTRACT

Method and apparatus for uplink transmission using multiple antennas are disclosed. A wireless transmit/receive unit (WTRU) performs space time transmit diversity (STTD) encoding on an input stream of a physical channel configured for STTD. Each physical channel may be mapped to either an in-phase (I) branch or a quadrature-phase (Q) branch. The WTRU may perform the STTD encoding either in a binary domain or in a complex domain. Additionally, the WTRU may perform pre-coding on at least one physical channel including the E-DPDCH with the pre-coding weights, and transmitting the pre-coded output streams via a plurality of antennas. The pre-coding may be performed either after or before spreading operation.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application Nos.61/247,123 filed Sep. 30, 2009; 61/248,313 filed Oct. 2, 2009; and61/356,320 filed Jun. 18, 2010, the contents of which is herebyincorporated by reference herein.

BACKGROUND

Techniques for using multiple antennas have been used in cellularwireless communication systems as an effective means to improverobustness of data transmission and achieve higher data throughput. Oneof the multiple antenna techniques is space-time block coding (STBC).STBC is based on introducing joint correlations in transmitted signalsin both the space and time domains to provide transmit diversity tocombat fading channels.

The Alamouti scheme is the space-time block code to provide transmitdiversity for systems with two transmit antennas. The Alamouti-basedspace-time block code has been widely used because of its simplicity andno need for the transmitter to know the channel state information (CSI)and therefore no need of channel feedback. Due to its effectiveness andeasy implementation, the Alamouti-based space-time block code has beenadopted into many wireless systems, such as WiMAX and WiFi. In thirdgeneration partnership project (3GPP), it was introduced in downlinktransmissions in universal mobile telecommunication system (UMTS) sinceRelease 99 and also adopted in downlink high speed downlink packetaccess (HSDPA) over higher speed data channels in Release 5. In the 3GPPstandard, the implementation of Alamouti scheme is known as space timetransmit diversity (STTD).

Enhanced uplink (EU), (also known as high speed uplink packet access(HSUPA)), is a feature that was introduced in 3GPP Release 6 to providehigher data rates in the uplink of UMTS wireless systems. The HSUPA maybe configured to allow for much faster scheduling of uplinktransmissions as well as lower overall data transmission latency.

Multiple antenna transmission/reception techniques with advanced signalprocessing are often referred to as multiple-input multiple-output(MIMO). MIMO has been widely studied and may significantly improve theperformance of wireless communication systems.

Multiple antenna techniques have been widely adopted in many wirelesscommunication systems such as IEEE 802.11n based wireless local areanetwork access points and cellular systems like wideband code divisionmultiple access (WCDMA)/high speed packet access (HSPA) and long termevolution (LTE). MIMO is introduced in WiMAX as well as in 3GPP. Moreadvanced MIMO enhancements are currently being studied for 3GPP Release9 and 10. Currently, only downlink (DL) MIMO is specified in 3GPP WCDMAstandard.

SUMMARY

Method and apparatus for uplink transmission using multiple antennas aredisclosed. A wireless transmit/receive unit (WTRU) performs space timetransmit diversity (STTD) encoding on an input stream of a physicalchannel configured for STTD. Each physical channel may be mapped toeither an in-phase (I) branch or a quadrature-phase (Q) branch. The STTDencoding generates a plurality of output streams such that the inputstream is not changed for one output stream, and symbols of the inputstream is switched and a constellation point of one symbol is changed toan opposite constellation point on an I branch or a Q branch for theother output stream. All configured physical channels on an I branch anda Q branch are combined, respectively, to generate a plurality ofcombined streams in a complex format, and the combined streams aretransmitted via a plurality of antennas.

The physical channel configured for STTD may include at least one of anenhanced dedicated channel (E-DCH) dedicated physical data channel(E-DPDCH), an E-DCH dedicated physical control channel (E-DPCCH), a highspeed dedicated physical control channel (HS-DPCCH), a dedicatedphysical control channel (DPCCH), and a dedicated physical data channel(DPDCH).

The WTRU may perform the STTD encoding either in a binary domain or in acomplex domain. For the complex domain STTD encoding, the STTD encodingis performed on a block of complex-valued chips corresponding to one oran integer multiple of a largest spreading factor among the physicalchannels.

A WTRU may perform pre-coding on at least one type of uplink physicalchannel including the E-DPDCH with the pre-coding weights, andtransmitting the pre-coded output streams via a plurality of antennas.Either multiple E-DPDCH data streams may be transmitted usingmultiple-input multiple-output (MIMO) or a single E-DPDCH data streammay be transmitted using a closed loop transmit diversity depending onthe E-DPDCH configuration. The pre-coding may be performed either afteror before the spreading operation.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description,given by way of example in conjunction with the accompanying drawingswherein:

FIG. 1A is a system diagram of an example communications system in whichone or more disclosed embodiments may be implemented;

FIG. 1B is a system diagram of an example wireless transmit/receive unit(WTRU) that may be used within the communications system illustrated inFIG. 1A;

FIG. 1C is a system diagram of an example radio access network and anexample core network that may be used within the communications systemillustrated in FIG. 1A;

FIG. 2 shows an STTD transmitter in accordance with one embodiment;

FIG. 3 shows an STTD transmitter in accordance with another embodiment;

FIG. 4 shows an STTD transmitter in accordance with another embodiment;

FIG. 5 shows an STTD transmitter in accordance with another embodiment;

FIG. 6 shows an STTD transmitter in accordance with another embodiment;

FIG. 7 shows an STTD transmitter in accordance with another embodiment;

FIG. 8 shows an STTD transmitter in accordance with another embodiment;

FIGS. 9(A)-9(D) show transmission schemes for the non-STTD channel(s);

FIGS. 10(A) and 10(B) show example binary STTD encoders for binary phaseshift keying (BPSK) modulated data transmission;

FIGS. 11(A) and 11(B) show example STTD encoders for 4-level pulseamplitude modulation (4PAM) modulation;

FIGS. 12(A) and 12(B) show example STTD encoders for 8PAM;

FIG. 13 shows an example transmitter structure with a dual binary STTDencoder;

FIG. 14 shows an example STTD transmitter with a complex STTD encoder;

FIG. 15 shows an example complex STTD encoding process;

FIG. 16 shows STTD symbol configuration with different spreading factors(SFs);

FIG. 17 illustrates an exemplary complex STTD encoding applied to theHSUPA data channels;

FIG. 18 shows the corresponding block encoder in accordance with thisembodiment;

FIG. 19 shows an example transmitter in accordance with one embodiment;

FIG. 20 shows an example transmitter in accordance with anotherembodiment;

FIG. 21 shows an example transmitter in accordance with anotherembodiment;

FIG. 22 shows an example transmitter in accordance with anotherembodiment;

FIG. 23 shows an example transmitter in accordance with anotherembodiment;

FIG. 24 shows an example transmitter in accordance with anotherembodiment;

FIG. 25 shows an example transmitter in accordance with anotherembodiment;

FIG. 26 shows the spreading operation, which includes spreading with agiven channelization code, weighting, and IQ phase mapping;

FIG. 27 shows an example pre-coder for the dual stream case;

FIG. 28 shows another example pre-coder for the dual stream case;

FIG. 29 shows another example pre-coder for the dual stream case;

FIG. 30 shows an example transmitter for the two stream case;

FIG. 31A shows an example UPCI signaling using an E-HICH;

FIG. 31B illustrates the case where one out of seven E-HICH subframescarries the UPCI field;

FIG. 32 shows an example transmitter for transmitting uplink precodingcontrol information (UPCI) for two WTRUs via an E-DCH channel stateinformation channel (E-CSICH) in accordance with one embodiment;

FIG. 33 shows another example transmitter for transmitting UPCI for twoWTRUs via an E-CSICH in accordance with another embodiment;

FIG. 34 shows another example transmitter for transmitting UPCI for twoWTRUs via an E-CSICH in accordance with another embodiment;

FIG. 35 shows an F-DPCH format in accordance with this embodiment;

FIGS. 36 and 37 show signaling of PHI and POI using the transmitterstructure shown in FIGS. 32 and 34, respectively;

FIGS. 38 and 39 show signaling of UPCI and rank indication (RI) usingthe transmitter structure shown in FIGS. 32 and 34, respectively;

FIG. 40 shows an example frame format for the E-CSICH.

DETAILED DESCRIPTION

FIG. 1A is a diagram of an example communications system 100 in whichone or more disclosed embodiments may be implemented. The communicationssystem 100 may be a multiple access system that provides content, suchas voice, data, video, messaging, broadcast, etc., to multiple wirelessusers. The communications system 100 may enable multiple wireless usersto access such content through the sharing of system resources,including wireless bandwidth. For example, the communications systems100 may employ one or more channel access methods, such as code divisionmultiple access (CDMA), time division multiple access (TDMA), frequencydivision multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrierFDMA (SC-FDMA), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, 102 d, a radioaccess network (RAN) 104, a core network 106, a public switchedtelephone network (PSTN) 108, the Internet 110, and other networks 112,though it will be appreciated that the disclosed embodiments contemplateany number of WTRUs, base stations, networks, and/or network elements.Each of the WTRUs 102 a, 102 b, 102 c, 102 d may be any type of deviceconfigured to operate and/or communicate in a wireless environment. Byway of example, the WTRUs 102 a, 102 b, 102 c, 102 d may be configuredto transmit and/or receive wireless signals and may include userequipment (UE), a mobile station, a fixed or mobile subscriber unit, apager, a cellular telephone, a personal digital assistant (PDA), asmartphone, a laptop, a netbook, a personal computer, a wireless sensor,consumer electronics, and the like.

The communications systems 100 may also include a base station 114 a anda base station 114 b. Each of the base stations 114 a, 114 b may be anytype of device configured to wirelessly interface with at least one ofthe WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to one or morecommunication networks, such as the core network 106, the Internet 110,and/or the networks 112. By way of example, the base stations 114 a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a HomeNode B, a Home eNode B, a site controller, an access point (AP), awireless router, and the like. While the base stations 114 a, 114 b areeach depicted as a single element, it will be appreciated that the basestations 114 a, 114 b may include any number of interconnected basestations and/or network elements.

The base station 114 a may be part of the RAN 104, which may alsoinclude other base stations and/or network elements (not shown), such asa base station controller (BSC), a radio network controller (RNC), relaynodes, etc. The base station 114 a and/or the base station 114 b may beconfigured to transmit and/or receive wireless signals within aparticular geographic region, which may be referred to as a cell (notshown). The cell may further be divided into cell sectors. For example,the cell associated with the base station 114 a may be divided intothree sectors. Thus, in one embodiment, the base station 114 a mayinclude three transceivers, i.e., one for each sector of the cell. Inanother embodiment, the base station 114 a may employ multiple-inputmultiple output (MIMO) technology and, therefore, may utilize multipletransceivers for each sector of the cell.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 116, which may beany suitable wireless communication link (e.g., radio frequency (RF),microwave, infrared (IR), ultraviolet (UV), visible light, etc.). Theair interface 116 may be established using any suitable radio accesstechnology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 104 and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Universal MobileTelecommunications System (UMTS) Terrestrial Radio Access (UTRA), whichmay establish the air interface 116 using wideband CDMA (WCDMA). WCDMAmay include communication protocols such as High-Speed Packet Access(HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed DownlinkPacket Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).

In another embodiment, the base station 114 a and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Evolved UMTSTerrestrial Radio Access (E-UTRA), which may establish the air interface116 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.16 (i.e.,Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), InterimStandard 95 (IS-95), Interim Standard 856 (IS-856), Global System forMobile communications (GSM), Enhanced Data rates for GSM Evolution(EDGE), GSM EDGE (GERAN), and the like.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, and the like. In oneembodiment, the base station 114 b and the WTRUs 102 c, 102 d mayimplement a radio technology such as IEEE 802.11 to establish a wirelesslocal area network (WLAN). In another embodiment, the base station 114 band the WTRUs 102 c, 102 d may implement a radio technology such as IEEE802.15 to establish a wireless personal area network (WPAN). In yetanother embodiment, the base station 114 b and the WTRUs 102 c, 102 dmay utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1A,the base station 114 b may have a direct connection to the Internet 110.Thus, the base station 114 b may not be required to access the Internet110 via the core network 106.

The RAN 104 may be in communication with the core network 106, which maybe any type of network configured to provide voice, data, applications,and/or voice over internet protocol (VoIP) services to one or more ofthe WTRUs 102 a, 102 b, 102 c, 102 d. For example, the core network 106may provide call control, billing services, mobile location-basedservices, pre-paid calling, Internet connectivity, video distribution,etc., and/or perform high-level security functions, such as userauthentication. Although not shown in FIG. 1A, it will be appreciatedthat the RAN 104 and/or the core network 106 may be in direct orindirect communication with other RANs that employ the same RAT as theRAN 104 or a different RAT. For example, in addition to being connectedto the RAN 104, which may be utilizing an E-UTRA radio technology, thecore network 106 may also be in communication with another RAN (notshown) employing a GSM radio technology.

The core network 106 may also serve as a gateway for the WTRUs 102 a,102 b, 102 c, 102 d to access the PSTN 108, the Internet 110, and/orother networks 112. The PSTN 108 may include circuit-switched telephonenetworks that provide plain old telephone service (POTS). The Internet110 may include a global system of interconnected computer networks anddevices that use common communication protocols, such as thetransmission control protocol (TCP), user datagram protocol (UDP) andthe internet protocol (IP) in the TCP/IP internet protocol suite. Thenetworks 112 may include wired or wireless communications networks ownedand/or operated by other service providers. For example, the networks112 may include another core network connected to one or more RANs,which may employ the same RAT as the RAN 104 or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities, i.e., theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks. For example, the WTRU 102 c shown in FIG. 1A may be configured tocommunicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology.

FIG. 1B is a system diagram of an example WTRU 102. As shown in FIG. 1B,the WTRU 102 may include a processor 118, a transceiver 120, atransmit/receive element 122, a speaker/microphone 124, a keypad 126, adisplay/touchpad 128, non-removable memory 106, removable memory 132, apower source 134, a global positioning system (GPS) chipset 136, andother peripherals 138. It will be appreciated that the WTRU 102 mayinclude any sub-combination of the foregoing elements while remainingconsistent with an embodiment.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, thetransmit/receive element 122 may be an antenna configured to transmitand/or receive RF signals. In another embodiment, the transmit/receiveelement 122 may be an emitter/detector configured to transmit and/orreceive IR, UV, or visible light signals, for example. In yet anotherembodiment, the transmit/receive element 122 may be configured totransmit and receive both RF and light signals. It will be appreciatedthat the transmit/receive element 122 may be configured to transmitand/or receive any combination of wireless signals.

In addition, although the transmit/receive element 122 is depicted inFIG. 1B as a single element, the WTRU 102 may include any number oftransmit/receive elements 122. More specifically, the WTRU 102 mayemploy MIMO technology. Thus, in one embodiment, the WTRU 102 mayinclude two or more transmit/receive elements 122 (e.g., multipleantennas) for transmitting and receiving wireless signals over the airinterface 116.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 106 and/or the removable memory 132.The non-removable memory 106 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 116 from abase station (e.g., base stations 114 a, 114 b) and/or determine itslocation based on the timing of the signals being received from two ormore nearby base stations. It will be appreciated that the WTRU 102 mayacquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, and the like.

FIG. 1C is a system diagram of the RAN 104 and the core network 106according to an embodiment. As noted above, the RAN 104 may employ aUTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102 cover the air interface 116. The RAN 104 may also be in communicationwith the core network 106. As shown in FIG. 1C, the RAN 104 may includeNode-Bs 140 a, 140 b, 140 c, which may each include one or moretransceivers for communicating with the WTRUs 102 a, 102 b, 102 c overthe air interface 116. The Node-Bs 140 a, 140 b, 140 c may each beassociated with a particular cell (not shown) within the RAN 104. TheRAN 104 may also include RNCs 142 a, 142 b. It will be appreciated thatthe RAN 104 may include any number of Node-Bs and RNCs while remainingconsistent with an embodiment.

As shown in FIG. 1C, the Node-Bs 140 a, 140 b may be in communicationwith the RNC 142 a. Additionally, the Node-B 140 c may be incommunication with the RNC142 b. The Node-Bs 140 a, 140 b, 140 c maycommunicate with the respective RNCs 142 a, 142 b via an Iub interface.The RNCs 142 a, 142 b may be in communication with one another via anIur interface. Each of the RNCs 142 a, 142 b may be configured tocontrol the respective Node-Bs 140 a, 140 b, 140 c to which it isconnected. In addition, each of the RNCs 142 a, 142 b may be configuredto carry out or support other functionality, such as outer loop powercontrol, load control, admission control, packet scheduling, handovercontrol, macrodiversity, security functions, data encryption, and thelike.

The core network 106 shown in FIG. 1C may include a media gateway (MGW)144, a mobile switching center (MSC) 146, a serving GPRS support node(SGSN) 148, and/or a gateway GPRS support node (GGSN) 150. While each ofthe foregoing elements are depicted as part of the core network 106, itwill be appreciated that any one of these elements may be owned and/oroperated by an entity other than the core network operator.

The RNC 142 a in the RAN 104 may be connected to the MSC 146 in the corenetwork 106 via an IuCS interface. The MSC 146 may be connected to theMGW 144. The MSC 146 and the MGW 144 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices.

The RNC 142 a in the RAN 104 may also be connected to the SGSN 148 inthe core network 106 via an IuPS interface. The SGSN 148 may beconnected to the GGSN 150. The SGSN 148 and the GGSN 150 may provide theWTRUs 102 a, 102 b, 102 c with access to packet-switched networks, suchas the Internet 110, to facilitate communications between and the WTRUs102 a, 102 b, 102 c and IP-enabled devices.

As noted above, the core network 106 may also be connected to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

It should be noted that although the embodiments will be describedhereinafter in the context of 3GPP WCDMA, they are also applicable toany other wireless communication systems including, but not limited to,3GPP LTE, LTE-Advanced, general packet radio services (GPRS), CDMA2000,WiMAX, WiFi, IEEE 802.x systems, and the like.

In 3GPP WCDMA, different uplink channels may be configured for differentpurposes and applications. A dedicated physical control channel (DPCCH)and a dedicated physical data channel (DPDCH) are the control and datachannels introduced in Release 99. High speed downlink packet access(HSDPA) was introduced in Release 5, and a high speed dedicated physicalcontrol channel (HS-DPCCH) serves as a control channel for the HSDPAservices. The HS-DPCCH carries channel quality indication and hybridautomatic repeat request (HARQ) acknowledgement. In Release 6, enhanceddedicated channel (E-DCH) services have been introduced. An E-DCHdedicated physical control channel (E-DPCCH) and an E-DCH dedicatedphysical data channel (E-DPDCH) are the control and data channels forE-DCH services. The DPCCH is used to enable channel estimation at theNode-Bs, to maintain a stable power control loop, and to providebaseline reference for all other channels in terms of error rate controland grant allocation.

The STTD encoding may be implemented with two or more transmit antennas,each of which may be associated with its own transmit chain includingmodulation mapper, spreader, I/Q combining, scrambler, and separateradio frontend. Hereafter, the embodiments will be explained withreference to the STTD transmitter with two transmit antennas. However,it should be noted that the embodiments may be extended to any number oftransmit antennas and to any type of spatial diversity or spatialmultiplexing multiple antenna transmission techniques.

The STTD encoder, as will be described in detail below, performsspace-time processing over the data stream or signal to be transmittedand distributes its outputs to the two or more transmit chains. Afterthe STTD encoder, the signals operate independently without interactionbetween the two or more transmit chains.

FIG. 2 shows an STTD transmitter 200 in accordance with one embodiment.In accordance with this embodiment, the STTD encoding may be applied toa high speed uplink data channel(s), (i.e., an E-DPDCH), and it may notbe applied to other channels. The STTD transmitter 200 comprises a firstphysical layer processing block 202, an STTD processing block 204,second physical layer processing blocks 206, third physical layerprocessing blocks 208, channel combiners 210, and scramblers 212.

The first, second, and third physical layer processing blocks 202, 206,208 may perform the conventional signal processing functions includingmodulation mapping, channelization code spreading, gain scaling, and I/Qcombining, or any other functions. FIG. 2 shows that the STTD processingblock 204 is placed between the first and second physical processingblocks 202, 206, but the STTD processing block 204 may be placed at anystage of the physical layer processing, and the functions performed bythe first and second physical layer processing blocks 202, 206 may beconfigured differently.

One or more E-DPDCHs may be configured for a WTRU. The E-DPDCH(s) isprocessed by the first physical layer processing block 202 and thenprocessed by the STTD processing block 204. The STTD processing block204 outputs two or more signal streams depending on the number oftransmit antennas. The STTD processing block 204 performs either binarySTTD encoding or complex STTD encoding, and may perform the STTDencoding either on a bit/symbol level or on a block level, which will beexplained in detail below. If multiple E-DPDCHs are configured, multipleE-DPDCHs may be processed individually or jointly depending on the STTDencoder structure. The physical channels, (i.e., E-DPDCHs), areinitially formed as real valued and each physical channel may be mappedto either I branch or Q branch. At I/Q combining stage in the physicallayer processing block (either the first physical layer processing block202 or the second physical layer processing block 206), the physicalchannels mapped to either the I branch or the Q branch to form complexsignals. Non-STTD channels are processed by the third physical layerprocessing block(s) 208. Which non-STTD channel is mapped to whichtransmit antenna is explained in detail below. The channel combiningblock 210 on each transmit path merges the signal streams from all thechannels mapped to the corresponding antenna including the non-STTDchannels and E-DPDCHs into a complex signal. The channel combined signalstreams are then scrambled by scramblers 212 and transmitted via theantennas.

FIG. 3 shows an STTD transmitter 300 in accordance with anotherembodiment. In accordance with this embodiment, the STTD encoding isperformed on HSUPA channels, (i.e., an E-DPDCH(s) and an E-DPCCH), andit may not be applied to other channels. The STTD transmitter 300comprises first physical layer processing blocks 302 a, 302 b, STTDprocessing blocks 304 a, 304 b, second physical layer processing blocks306 a, 306 b, third physical layer processing blocks 308, channelcombiners 310, and scramblers 312.

The first, second, and third physical layer processing blocks 302 a/302b, 306 a, 306 b, 308 may perform the conventional signal processingfunctions including modulation mapping, channelization code spreading,gain scaling, and I/Q combining, or any other functions. FIG. 3 showsthat the STTD processing blocks 304 a/304 b are placed between the firstand second physical processing blocks 302 a/302 b and 306 a/306 b, butthe STTD processing blocks 304 a/304 b may be placed at any stage of thephysical layer processing, and the functions performed by the first andsecond physical layer processing blocks 302 a/302 b, 306 a/306 b may beconfigured differently.

The E-DPCCH is processed by the first physical layer processing block302 a and then processed by the STTD processing block 304 a. One or moreE-DPDCHs may be configured for a WTRU. The E-DPDCH(s) is processed bythe first physical layer processing block 302 b and then processed bythe STTD processing block 304 b. Each of the STTD processing blocks 304a/304 b outputs two or more signal streams depending on the number oftransmit antennas. The STTD processing blocks 304 a/304 b perform eitherbinary STTD encoding or complex STTD encoding, and may perform the STTDencoding either on a bit/symbol level or on a block level, which will beexplained in detail below. If multiple E-DPDCHs are configured, multipleE-DPDCHs may be processed individually or jointly depending on the STTDencoder structure. The physical channels, (i.e., E-DPDCHs, E-DPCCH), areinitially formed as real valued and each physical channel may be mappedto either I branch or Q branch. At I/Q combining stage in the physicallayer processing block (either the first physical layer processing block302 a/302 b or the second physical layer processing block 306 a/306 b),the physical channels are mapped to either the I branch or the Q branchto form complex signals. Non-STTD channels are processed by the thirdphysical layer processing block(s) 308. The channel combining block 310on each transmit path merges the signal streams from all the channelsmapped to the corresponding antenna including the non-STTD channels,E-DPDCHs, and E-DPCCH into a complex signal. The channel combined signalstreams are then scrambled by scramblers 312 and transmitted via theantennas.

With the STTD transmitter of FIG. 3, the reliability of the E-DPCCHassociated with the high speed data channel is improved correspondinglyby the transmit diversity. Thus, user throughput at cell edge will beenhanced without imposing the need of increasing the transmit power ofthe control channel. This may allow the E-DPCCH to have similar level ofreliability with respect to the E-DPDCH.

FIG. 4 shows an STTD transmitter in accordance with another embodiment.In accordance with this embodiment, the STTD encoding is performed onthe uplink control channels, (i.e., a DPCCH, an E-DPCCH, and anHS-DPCCH), and it may not be applied to other channels. The STTDtransmitter 400 comprises first physical layer processing blocks 402 a,402 b, 402 c, STTD processing blocks 404 a, 404 b, 404 c, secondphysical layer processing blocks 406 a, 406 b, 406 c, third physicallayer processing blocks 408, channel combiners 410, and scramblers 412.

The first, second, and third physical layer processing blocks 402 a, 402b, 402 c, 406 a, 406 b, 406 c, 408 may perform the conventional signalprocessing functions including modulation mapping, channelization codespreading, gain scaling, and I/Q combining, or any other functions. FIG.4 shows that the STTD processing blocks 404 a/404 b/404 c are placedbetween the first and second physical processing blocks 402 a/402 b/402c and 406 a/406 b/406 c, but the STTD processing block 404 a, 404 b, 404c may be placed at any stage of the physical layer processing, and thefunctions performed by the first and second physical layer processingblocks 402 a/402 b/402 c, 406 a/406 b/406 c may be configureddifferently.

The HS-DPCCH is processed by the first physical layer processing block402 a and then processed by the STTD processing block 404 a. The DPCCHis processed by the first physical layer processing block 402 b and thenprocessed by the STTD processing block 404 b. The DPCCH carries pilotsymbols. Therefore, in accordance with this embodiment, the pilotsymbols are also STTD encoded. The E-DPCCH is processed by the firstphysical layer processing block 402 c and then processed by the STTDprocessing block 404 c. Each of the STTD processing blocks 404 a/404b/404 c outputs two or more signal streams depending on the number oftransmit antennas. The STTD processing blocks 404 a/404 b/404 c performeither binary STTD encoding or complex STTD encoding, and may performthe STTD encoding either on a bit/symbol level or on a block level,which will be explained in detail below. The physical channels, (i.e.,E-DPCCH, DPCCH, HS-DPCCH), are initially formed as real valued and eachphysical channel may be mapped to either I branch or Q branch. At I/Qcombining stage in the physical layer processing block (either the firstphysical layer processing block 402 a/402 b/402 c or the second physicallayer processing block 406 a/406 b/406 c), the physical channels aremapped to either the I branchl branch or the Q branch to form complexsignals. Non-STTD channels are processed by the third physical layerprocessing block(s) 408. The channel combining block 410 on eachtransmit path merges the signal streams from all the channels mapped tothe corresponding antenna including the non-STTD channels, E-DPCCH,DPCCH, and HS-DPCCH into a complex signal. The channel combined signalstreams are then scrambled by scramblers 412 and transmitted via theantennas.

FIG. 5 shows an STTD transmitter 500 in accordance with anotherembodiment. In accordance with this embodiment, the STTD encoding isperformed on data channels, (i.e., a DPDCH(s), an E-DPDCH(s)), and itmay not be applied to other channels. The STTD transmitter 500 comprisesfirst physical layer processing blocks 502 a, 502 b, STTD processingblocks 504 a, 504 b, second physical layer processing blocks 506 a, 506b, third physical layer processing blocks 508, channel combiners 510,and scramblers 512.

The first, second, and third physical layer processing blocks 502 a, 502b, 506 a, 506 b, 508 may perform the conventional signal processingfunctions including modulation mapping, channelization code spreading,gain scaling, and I/Q combining, or any other functions. FIG. 5 showsthat the STTD processing blocks 504 a/504 b are placed between the firstand second physical processing blocks 502 a/502 b and 506 a/506 b, butthe STTD processing blocks 504 a/504 b may be placed at any stage of thephysical layer processing, and the functions performed by the first andsecond physical layer processing blocks 502 a/502 b, 506 a/506 b may beconfigured differently.

One or more DPDCH and/or one or more E-DPDCH(s) may be configured for aWTRU. The DPDCH(s) is processed by the first physical layer processingblock 402 a and then processed by the STTD processing block 404 a. TheE-DPDCH(s) is processed by the first physical layer processing block 402b and then processed by the STTD processing block 404 b. Each of theSTTD processing blocks 404 a/404 b outputs two or more signal streamsdepending on the number of transmit antennas. The STTD processing blocks404 a/404 b perform either binary STTD encoding or complex STTDencoding, and may perform the STTD encoding either on a bit/symbol levelor on a block level, which will be explained in detail below. Ifmultiple DPDCHs and/or E-DPDCHs are configured, multiple DPDCHs and/orE-DPDCHs may be processed individually or jointly depending on the STTDencoder structure. The physical channels, (i.e., DPDCH(s) andE-DPDCH(s)), are initially formed as real valued and each physicalchannel may be mapped to either I branch or Q branch. At I/Q combiningstage in the physical layer processing block (either the first physicallayer processing block 502 a/502 b or the second physical layerprocessing block 506 a/506 b), the physical channels are mapped toeither the I branch or the Q branch to form complex signals. Non-STTDchannels are processed by the third physical layer processing block(s)508. The channel combining block 510 on each transmit path merges thesignal streams from all the channels mapped to the corresponding antennaincluding the non-STTD channels, DPDCH(s), and E-DPDCHs into a complexsignal. The channel combined signal streams are then scrambled byscramblers 512 and transmitted via the antennas.

FIG. 6 shows an STTD transmitter 600 in accordance with anotherembodiment. In accordance with this embodiment, STTD encoding isperformed on all uplink channels, (E-DPDCH(s), E-DPCCH, DPDCH(s), DPCCH,HS-DPCCH). The STTD transmitter 600 comprises first physical layerprocessing blocks 602 a, 602 b, 602 c, 602 d, 602 e, STTD processingblocks 604 a, 604 b, 604 c, 604 d, 604 e, second physical layerprocessing blocks 606 a, 606 b, 606 c, 606 d, 606 e, channel combiners610, and scramblers 612.

The first, second, and third physical layer processing blocks 602 a, 602b, 602 c, 602 d, 602 e, 606 a, 606 b, 606 c, 606 d, 606 e, 608 mayperform the conventional signal processing functions includingmodulation mapping, channelization code spreading, gain scaling, and I/Qcombining, or any other functions. FIG. 6 shows that the STTD processingblocks 604 a/604 b/604 c/606 d/606 e are placed between the first andsecond physical processing blocks 602 a/602 b/602 c/602 d/602 e and 606a/606 b/606 c/606 d/606 e, but the STTD processing block 604 a, 604 b,604 c, 604 d, 604 e may be placed at any stage of the physical layerprocessing, and the functions performed by the first and second physicallayer processing blocks 602 a/602 b/602 c/602 d/602 e, 606 a/606 b/606c/606 d/606 e may be configured differently.

The E-DPCCH is processed by the first physical layer processing block602 a and then processed by the STTD processing block 604 a. One or moreDPDCH and/or one or more E-DPDCH(s) may be configured for a WTRU. TheE-DPDCH(s) is processed by the first physical layer processing block 602b and then processed by the STTD processing block 604 b. The DPCCH isprocessed by the first physical layer processing block 602 c and thenprocessed by the STTD processing block 604 c. The DPCCH carries pilotsymbols. Therefore, in accordance with this embodiment, the pilotsymbols are also STTD encoded. The DPDCH(s) is processed by the firstphysical layer processing block 602 d and then processed by the STTDprocessing block 604 d. The HS-DPCCH is processed by the first physicallayer processing block 602 e and then processed by the STTD processingblock 604 e. Each of the STTD processing blocks 604 a/604 b/604 c/604d/604 e outputs two or more signal streams depending on the number oftransmit antennas. The STTD processing blocks 604 a/604 b/604 c/604d/604 e perform either binary STTD encoding or complex STTD encoding,and may perform the STTD encoding either on a bit/symbol level or on ablock level, which will be explained in detail below. The physicalchannels, (i.e., E-DPCCH, DPCCH, HS-DPCCH), are initially formed as realvalued and each physical channel may be mapped to either I branch or Qbranch. At I/Q combining stage in the physical layer processing block(either the first physical layer processing block 602 a/602 b/602 c/602d/602 e or the second physical layer processing block 606 a/606 b/606c/606 d/606 e), the physical channels are mapped to either the I branchor the Q branch to form complex signals. The channel combining block 610on each transmit path merges the signal streams from all the channelsmapped to the corresponding antenna including E-DPCCH, E-DPDCH(s),DPCCH, DPDCH(s), and HS-DPCCH into a complex signal. The channelcombined signal streams are then scrambled by scramblers 612 andtransmitted via the antennas.

The advantage of the STTD transmitter in FIG. 6 is that channels (bothdata and control channels) are all balanced in terms of the servicequality therefore the power scaling configuration on each channel may bemaintained the same as if no STTD is applied as long as the powercontrol is performed properly according to the specifiedsignal-to-interference ratio (SIR) or block error rate (BLER) target.Since the pilot signal transmitted in the DPCCH over the two antennasmay be made orthogonal at the receiver with the appropriate STTDprocessing, the channel estimation at the Node-B may be readilyconducted without introducing the second pilot signal.

The peak-to-average power ratio (PAPR) or the cubic metric of all theSTTD transmitter structures disclosed above may maintain the similarlevel at each antenna as the conventional uplink implementation, sincethe STTD processing is applied per data symbol basis that does notintroduce dependency between symbols across time. This behavior may beunderstood by the fact that the STTD processing may be implemented inbinary or symbol domain (as opposed to the chip domain) as shown below.

FIG. 7 shows an STTD transmitter in accordance with another embodiment.In this embodiment, all channels except the DPCCH are STTD processed.Because the pilot signal is embedded in the DPCCH, this structure mayoffer the benefit of not requiring significant modification of thechannel estimation at the Node-B receiver side. The STTD transmitter inFIG. 7 is substantially similar to the STTD transmitter in FIG. 6.Therefore, it will not be explained in detail for simplicity.

FIG. 8 shows an STTD transmitter in accordance with another embodiment.In this embodiment, E-DPCCH, E-DPDCH(s), and HS-DPCCH are STTD encodedand DPDCH(s) and DPCCH are not STTD encoded. With this embodiment, themodification requirement at the Node-B receiver may be reduced. The STTDtransmitter in FIG. 7 is substantially similar to the STTD transmitterin FIG. 6. Therefore, it will not be explained in detail for simplicity.

The channels over which the STTD processing is not applied may betransmitted over at least one antenna. The non-STTD channel(s) may betransmitted over one of the antennas, as shown in FIG. 9(A).Alternatively, the identical signals of the non-STTD channel(s) may betransmitted over the two (or all) antennas, as shown in FIG. 9(B).Alternately, the non-STTD channel(s) may be transmitted over two (orall) antennas in a time division duplex fashion in accordance with aconfigured pattern, as shown in FIG. 9(C). Alternatively, any types ofspace time processing or multiple-input multiple-output (MIMO) schemesmay be used for transmission of the non-STTD channel(s), as illustratedin FIG. 9(D).

Different from the downlink in a UMTS communication system, the physicalchannels in the uplink are formed as real-valued sequences and fed intoeither the I branch or the Q branch of the complex channelindependently. Each of the physical channels is spread and weighted byits own channelization code and gain factor. As a result, the complexsignal generated in such way may not have the properties of a true twodimension constellation. It may exhibit imbalance in phase and amplitudebetween its I-phase and Q-phase components. Before sending to the radiofront end, a complex scrambler may be applied, and this helps to evenout the imbalance existing in the transmitted signal.

Embodiments for STTD encoder are disclosed hereafter. The STTD encodermay be a binary STTD encoder or a complex STTD encoder.

The binary STTD encoder operates in binary domain before the physicallayer processing, (i.e., prior to the modulation mapping). Assumingb_(i),i=0,1,2, . . . ,N where N is the number of bits per symbol, arethe bits to be transmitted, the STTD encoder manipulates these bits togenerate the inputs to create diversity for the two (or more) separatedantenna paths. Each channel may form real-valued information sequenceindependently, and the physical channels that may be placed on the I andQ branches separately may be treated by a different STTD encoder. TheSTTD encoding may then be performed separately for each I and Q branch.FIGS. 10(A) and 10(B) show example binary STTD encoders for binary phaseshift keying (BPSK) modulated data transmission. One of them may be usedfor an I-branch channel and the other may be used for a Q branchchannel. Each branch may use a different binary STTD encoder. The inputbit b_(i) may take three values 0,1, and discontinues transmission DTX).b _(i) is defined as follows: if b_(i)=0 then b _(i)=1, if b=1 then b_(i)=0, otherwise b _(i)=b_(i).

The dual binary STTD encoder configuration may vary depending on thesize of modulation mapping. FIGS. 11(A) and 11(B) show example STTDencoders with example constellation mapping rules for each branch for4-level pulse amplitude modulation (4PAM) modulation. One of them may beused for an I-branch channel and the other may be used for a Q-branchchannel.

The dual binary STTD encoder may be extended to other constellations ofany order. For example, constellation mapping rules for the STTDencoding in general may be as follows: (1) the data bits are taken fortwo consecutive symbols: b₀b₁ . . . b_(N-1)b_(N) . . . b_(2N-1), where Nis the number of bits in a symbol, (2) the binary data for antenna 1remains unchanged, (3) the order of two symbols is changed as follows togenerate the data for antenna 2: b₀b₁ . . . b_(N-1)b_(N) . . .b_(2N-1)→b_(N) . . . b_(2N-1) b₀b₁ . . . b_(N-1), and (4) aconstellation mapping rule is applied for the I-branch channels, wherebythe first bit of the second symbol is inverted: b_(N)→ b _(N), and forthe Q-branch channels, whereby the first bit of the first symbol isinverted: b₀→ b ₀ (alternatively, different bit position may be inverteddepending on the constellation mapping rule).

FIGS. 12(A) and 12(B) show example STTD encoders with constellationmapping rules for 8PAM. One of them may be used for an I-branch channeland the other may be used for a Q-branch channel.

FIG. 13 shows an example transmitter 1300 with a dual binary STTDencoder. The transmitter 1300 includes STTD encoders 1302, modulationmappers 1304, spreading blocks 1306, gain control blocks 1308, channelcombining blocks 1310, I/Q combining blocks 1312, and scrambling blocks1314. Each channel may be processed individually by the STTD encoder1302. Each STTD processing block 1302 outputs two or more signal streamsdepending on the number of transmit antennas. Each signal stream fromthe STTD encoder 1302 is then processed by a modulation mapper 1304, andthen by a spreading block 1306, and a gain control block 1308 with itsown channelization code and gain factor. The channel combining block1310 and the I/Q combining block 1312 merge all the channels into acomplex signal, which is scrambled by a scrambling block 1314 beforetransmitted over the assigned antenna. Since it is implemented in thebinary domain, the dual binary STTD encoder 1302 offers a simplesolution that allows an implementation to duplicate two transmit chains,one for each antenna, without having to make much modification ascompared to the conventional WTRU transmitter structure.

Since the symbol boundaries of all considered physical channels, (i.e.,DPCCH, DPDCH, E-DPCCH, E-DPDCH, and HS-DPCCH), are aligned at certaintime point, the STTD encoding may be performed in a complex domain. Dueto the fact that each channel is spread in real domain and the complexsignal comprises multiple channels, the STTD encoder should deal withdifferent symbol durations resulted from different spreading factors(SFs) among the channels as shown in the Table 1.

TABLE 1 Physical channel type SF Symbols/slot DPCCH 256 10 DPDCH 2, 4,8, . . . , 256 10, . . . , 1280 HS-DPCCH 256 10 E-DPCCH 256 10 E-DPDCH2, 4, 8, . . . , 256 10, . . . , 1280

FIG. 14 shows an example STTD transmitter 1400 with a complex STTDencoder. The transmitter 1400 comprises modulation mappers 1402 a, 1402b, spreading blocks 1404 a, 1404 b, gain control blocks 1406 a, 1406 b,channel and I/Q combining blocks1408 a, 1408 b, a complex STTD encoder1410, channel combining blocks 1412, and scrambling blocks 1414. STTDchannels are processed by a modulation mapper 1402 a, a spreading block1404 a, and a gain control block 1406 a, and combined into a complexsignal by the channel and I/Q combining block 1408 a. The combined STTDchannel signals are then processed by the complex STTD encoder 1410.Non-STTD channels are processed by a modulation mapper 1402 b, aspreading block 1404 b, and a gain control block 1406 b, and combinedinto a complex signal by the channel and I/Q combining block 1408 b. TheSTTD-encoded STTD channel signals and the processed non-STTD channelsignals are then combined by the channel combiners 1412, and thenprocessed by the respective scrambling blocks 1414 for transmission.

FIG. 15 shows an example complex STTD encoding process. It should benoted that the complex STTD encoding may be performed with any STTDtransmitters disclosed above. The uplink channels (DPCCH, DPDCH(s),HS-DPCCH, E-DPCCH, E-DPDCH(s)) are spread by a specific spreading block1502 with a specific channelization code with a specific spreadingfactor and combined to a complex signal by a combiner 1504. Thespreading factors for the uplink channels may be different. The combinedcomplex signal 1505, (i.e., a block of chips combined over multipleuplink channels, which will be referred to as “STTD symbol”), isscrambled by the scrambler 1506 and stored in buffers 1508 a, 1508 b intime alternation, (i.e., the switch 1507 switches every T time instant),so that two consecutive STTD symbols are processed by the STTD encoder1510 for STTD encoding.

The switch 1507 is synchronized to a symbol boundary as follows. Overthe complex signal, the STTD symbols are defined such that a symbolduration “T” equals to the length of data symbols from the channel witha largest spreading factor of value SF_(max), and the time boundary isaligned with the data symbols from the channel with the largestspreading factor of value SF_(max). Therefore, each STTD symbolcomprises SF_(max) chips. The complex STTD operation is then performedover the STTD symbols S0 and S1 as follows:

$\begin{matrix}\begin{matrix}\lbrack {s_{0}\mspace{25mu} s_{1}} \rbrack & { \Rightarrow\begin{bmatrix}s_{0} & s_{1} \\{- s_{1}^{*}} & s_{0}^{*}\end{bmatrix} ;}\end{matrix} & {{Equation}\mspace{14mu} (1)}\end{matrix}$

where * represents a complex conjugate. The complex conjugate andnegative operations are performed over the whole waveform of the STTDsymbols, or equivalently, over every chip of the spread complex signal.The matrix notation means that S₀ is transmitted first in its entiretyand then followed by S₁ in its entirety at the first antenna, and −S₁*is transmitted first in its entirety and then followed by S₀* in itsentirety at the second antenna. The receiver needs be aware of thesymbol configuration and boundary to perform decoding.

FIG. 16 shows an example STTD symbol configuration for channels withdifferent SFs, where each of the STTD symbols (S₀ or S₁) containsS_(SFmax) chips. The channels may take any combination of SFs in anyorder. Channel 1 is spread with the largest SF (SF_(max)), and the STTDsymbol of that channel contains one symbol of S_(SFmax) chips. Channel 2is spread with a half of the SF_(max), (i.e., SF_(max)/2), and the STTDsymbols of that channel contains two symbols, each comprisingS_(SFmax/2) chips. Channel N is spread with SF_(max)/k, and the STTDsymbols of that channel contains k symbols, each comprising S_(SFmax/k)chips. More than one channel may be spread with the same spreadingfactor and some spreading factors may not be used. For the channels thathave spreading factor equal to SF_(max), one information symbol istransmitted in an STTD symbol. The other channels may have more than oneinformation symbols included in an STTD symbol, depending on thespreading factor. As shown in FIG. 16, the number of data symbolscontained in an STTD symbol for a particular channel is determined bythe ratio of SF_(max) and SF associated to that channel. For example, ifa channel is spread with a spreading factor SF_(max)/2, then the channelmay have two data symbols per STTD symbol.

An exemplary complex STTD encoding applied to the high speed uplinkpacket access (HSUPA) data channels, (i.e., the E-DPDCHs), isillustrated hereafter with reference to FIG. 17. FIG. 17 shows anexample transmitter 1700 with a complex STTD encoder for transmission offour E-DPDCHs. The transmitter 1700 comprises modulation mappers 1702,channelization blocks 1704, gain control blocks 1706, channel combiners1708, an I/Q combiner 1710, and an STTD encoder 1712. In this example,the WTRU transmits at a peak uplink data rate, where four E-DPDCHs areconfigured for uplink data transmission allowing a total of 11.5 Mbps ofdata throughput. The channelization codes and spreading factors used forthese E-DPDCHs are specified in Table 2.

TABLE 2 E-DPDCH Channelization Spreading channels codes factor I/Q pathE-DPDCH1 C_(2,1) 2 I E-DPDCH2 C_(2,1) 2 Q E-DPDCH3 C_(4,1) 4 I E-DPDCH4C_(4,1) 4 Q

In this example, E-DPDCHs 1 and 3 are mapped to I branch, and E-DPDCHs 2and 4 are mapped to Q branch. The binary streams on each E-DPDCH aremapped to 4PAM symbols individually by the modulation mapper 1702. Eachof the E-DPDCHs is spread with a corresponding channelization code bythe channelization block 1704 and then scaled with a corresponding gainfactor by the gain control block 1706. The E-DPDCHs may take differentspreading factors, (i.e., 2 and 4 in this example). The outputs of theprocessing for each of the E-DPDCHs are the chips denoted by x₁(n),x₂(n), x₃(n), x₄(n), where n is the chip index.

E-DPDCHs 1 and 3 and E-DPDCHs 2 and 4 are then combined by the channelcombining blocks 1708, respectively, and then combined to a complexsignal by the I/Q combining block 1710. Combining the channels accordingto the I/Q path assignment listed in Table 2 yields:

x(n)=x ₁(n)+jx ₂(n)+x ₃(n)+jx ₄(n).   Equation (2)

After the complex STTD encoding by the STTD encoder 1712, the first STTDsymbol (even symbol) contains the following four chips:

s ₀ ={x(0), x(1), x(2), x(3)};   Equation (3)

and the second STTD symbol (odd symbol) contains the following fourchips:

s ₁ ={x(4), x(5), x(6), x(7)}.   Equation (4)

At antenna 1, So is transmitted first and followed by S₁, and at antenna2, −S₁* is transmitted first and then followed by S₀*. The sameprocedure is repeated for the even and odd STTD symbols.

The complex STTD encoding above may be extended to a longer symbolperiod. The STTD symbol may contain more than one data symbolcorresponding to the largest SF, which may allow longer diversitycoherence time to combat slow fading channels. The value “T” in FIG. 15,for example, may take an integer multiple of SF_(max) chips. FIG. 18shows a block STTD encoder in accordance with one embodiment. FIG. 18shows that the STTD symbol comprises more than one data symbol ofS_(SFmax) chips. More than one channel may be mapped to the samespreading factor. The complex STTD encoder may offer better timediversity and the cubic metric of second antenna may be less affected.This embodiment may be extended to the dual binary STTD encoderdescribed above with more bits in one symbol.

Embodiments for multi-antenna transmission schemes with pre-coding inthe uplink are disclosed hereafter.

In HSUPA, UL physical layer comprises multiple dedicated physicalchannels, including control channels, such as DPCCH, E-DPCCH andHS-DPCCH, and data channels, such as DPDCH and E-DPDCH. When a WTRU isconfigured in a UL MIMO mode, the WTRU performs E-DCH transport formatcombination (E-TFC) selection to schedule one or more transport blocksin every TTI. When only one transport block is scheduled, it may bemapped to the primary transport block.

Hereinafter, the following terminologies will be used. E-DPDCH1 andE-DPDCH2 are two sets of E-DPDCHs mapped to the primary and secondaryE-DCH data stream, which may also be referred to as primary andsecondary stream. E-DPDCH1 and E-DPDCH2 may comprise one or moreE-DPDCHs. E-DPDCH1 _(k) denotes the k^(th) physical E-DPDCH of theprimary E-DCH data stream, and E-DPDCH2 _(k) denotes the k^(th) physicalE-DPDCH of the secondary E-DCH data stream. DPDCH1 and DPDCH2 are twoset of DPDCHs mapped to the primary and secondary DPDCH data stream,respectively. DPDCH1 _(n) denotes the nth physical DPDCH of the primaryDPDCH data stream, where n=0, . . . ,N_(max-dpdch1). DPDCH2 _(n) denotesthe n^(th) physical DPDCH of the secondary DPDCH data stream, where n=0,. . . ,N_(max-dpdch2). It should be noted that the embodiments disclosedherein are mainly described with reference to dual-E-DCH streamtransmission, (i.e., both the primary E-DCH data stream and thesecondary E-DCH data stream), but the embodiments are equally applicableto a single E-DCH stream transmission.

The transmitter embodiments disclosed below show pre-coding for thedual-stream transmission, (i.e., two transport blocks: primary andsecondary transport blocks). It should be noted that all the transmitterembodiments disclosed below may operate with a single stream or multiplestreams. If a single stream needs to be transmitted, one transmit chainin the transmitter is utilized for transmission of the single stream. Ifdual stream is configured, primary and secondary E-DCH transport blockspass through the transport channel (TrCH) processing for E-DCH which mayinclude adding cyclic redundancy check (CRC) parity bits to thetransport block, code block segmentation, channel coding, physical layerhybrid automatic repeat request (HARQ), rate matching, physical channelsegmentation, interleaving and mapping to E-DPDCH1 and E-DPDCH2, and thelike. When only one transport block is scheduled, it may be mapped tothe primary transport block, using one signal chain.

FIG. 19 shows an example transmitter 1900 in accordance with oneembodiment. In this embodiment, the transmitter 1900 applies pre-codingoperation to both E-DPCCH and E-DPDCH after spreading operations. Byapplying the same precoding weights to both the E-DPDCH and the E-DPCCHof the same stream, both the E-DPDCH and the E-DPCCH may experiencesimilar propagation conditions. As a result, the conventional powersetting rules for the E-DPCCH and the E-DPDCH may be re-used.

The transmitter 1900 comprises physical layer processing blocks 1902 forE-DPDCH, spreading blocks 1904, 1906, 1914, combining blocks 1908, 1916,a precoder 1910, a weights selection block 1912, scramblers 1918,filters 1920, and antennas 1922. Primary and secondary E-DCH transportblocks, if dual-stream is configured, (or a primary E-DCH transportblock if one stream is configured), are processed by the physical layerprocessing blocks 1902 for E-DPDCH. The physical layer processing mayinclude adding CRC parity bits to the transport block, code blocksegmentation, channel coding, physical layer HARQ, rate matching,physical channel segmentation, interleaving and mapping to E-DPDCH1 andE-DPDCH2 if dual-stream is configured, respectively, (or to E-DPDCH1 ifa single stream is configured). Either E-DPDCH1 or E-DPDCH2 may compriseone or more E-DPDCHs depending on the E-TFCI selected for the primaryand secondary E-DCH transport blocks, which may or may not be the same.

After the physical layer processing, the data streams on the E-DPDCH1and the E-DPDCH2 are spread by the spreading blocks 1904, respectively.Spreading operations on the E-DPCCH1 and the E-DPCCH2 are also performedby the spreading blocks 1906. The E-DPCCH2 is present if there are twoE-DCH transport blocks being transmitted. In case where a single E-DCHstream is transmitted, the E-DPCCH2 may not be transmitted. After thespreading operation, the real-valued chips on the I and Q branches ofthe E-DPDCH(s) and the E-DPCCH(s) are summed by the combiners 1908 intotwo complex-valued streams. The two complex-valued streams are thenprocessed by the pre-coder 1910. The pre-coder 1910 applies pre-codingweights determined by the weights selection block 1912 to distribute thesignals to the antennas 1922. Depending on the number of transportblocks scheduled for transmission, the weights selection block 1912 mayprovide one or more sets of pre-coder weights. The pre-coding operationwill be explained in detail below.

For every pre-defined or configured period, (e.g., every TTI or slot),the pre-coder weights may be updated for the upcoming transmission.Based on the channel-dependent feedback information from the Node-B, theweights selection block 1912 may select the pre-coding weights, whichwill be explained in detail below.

After the precoding, and spreading on all other configured physicalchannels by spreading blocks 1914, the I and Q branches of all theconfigured physical channels, (e.g., DPCCH, DPDCH, HS-DPCCH, E-DPCCH,and E-DPDCH), are summed by the combiners 1916 into two complex-valuedstreams, which are then scrambled by the scramblers 1918 with one or twocomplex-valued scrambling codes. The WTRU then transmits data on bothantennas after filtering. The WTRU may signal the pre-coding weights onthe UL, which will be explained in detail below.

FIG. 19 shows that the precoding is performed after the spreading andcombining of the E-DPDCH(s) and E-DPCCH(s). However, the pre-codingoperation may be performed at any stage, either at the symbol or chiplevel, and may be applied to one or more data or control channels beforeor after spreading or scrambling operations depending on the pre-coder'slocation in the transmitter.

FIG. 20 shows an example transmitter 2000 in accordance with anotherembodiment. In this embodiment, the pre-coding is applied to theE-DPDCHs after spreading operation. The transmitter comprises physicallayer processing blocks 2002 for E-DPDCH, spreading blocks 2004, 2010,2014, combining blocks 2012, 2016, a precoder 2006, a weights selectionblock 2008, scramblers 2018, filters 2020, and antennas 2022. Primaryand secondary E-DCH transport blocks, if dual-stream is configured, (ora primary E-DCH transport block if one stream is configured), areprocessed by the physical layer processing blocks 2002 for E-DCH. Thephysical layer processing may include adding CRC parity bits to thetransport block, code block segmentation, channel coding, physical layerHARQ, rate matching, physical channel segmentation, interleaving andmapping to E-DPDCH1 and E-DPDCH2 if dual-stream is configured,respectively, (or to E-DPDCH1 if a single stream is configured).

After the physical layer processing, the data streams on the E-DPDCH1and E-DPDCH2 are spread by the spreading blocks 2004. After thespreading operation, the chip streams are processed by the precoder2006. The pre-coder 2006 applies pre-coding weights determined by theweights selection block 2008 to distribute the signals to the antennas2022. Depending on the number of transport blocks scheduled fortransmission, the weights selection block 2008 may provide one or moresets of pre-coder weights.

Spreading operation on the E-DPCCH1 and the E-DPCCH2, and all otherphysical channels is performed by the spreading blocks 2010, 2014,respectively. After the spreading operation on the E-DPCCH(s) and allother configured physical channels, the chips on the I and Q branches ofall the configured physical channels, (e.g., DPCCH, DPDCH, HS-DPCCH,E-DPCCH, and E-DPDCH), are summed by the combiners 2012, 2016 into twocomplex-valued streams, which are then scrambled by the scramblers 2018with one or two complex-valued scrambling codes. The WTRU then transmitsdata on both antennas after filtering.

In accordance with this embodiment, since control channels are notpre-coded, the conventional receiver may be used to receive the controlchannels without a need to inverse the spatial pre-coding operation forthe control information. Further, since the E-DPCCH is not pre-coded, itmay be decoded using a different receiver than the one for the E-DPDCH,which may expedite decoding of the transport block size, happy bit, andretransmission sequence number (RSN) information, thus reducing thedecoding latency.

In addition, the E-DPCCH reliability may be linked to the DPCCH, whichis power-controlled and experiences the same channel conditions. In thatway the reliability of the control channel becomes independent of thepre-coding. Further, compared with data channels, much strongerprotection may be given to the control channels so that they may bedemodulated and decoded correctly with much higher probability. Thecontrol channels may not be pre-coded since spatial multiplexing of twocontrol channels would generate inter-stream interferences andconsequently may cause performance degradation. Instead, to provideadditional transmit diversity gain and improve reception reliability tothe control channels, an open loop transmit diversity scheme such asspace time block coding (STBC) may be implemented.

In addition, since E-DPCCH1 and E-DPCCH2 are sent over the two differentantennas without pre-coding, both E-DPCCHs may be used as additionalpilot information (in decision directed mode) for improved channelestimation.

FIG. 21 shows an example transmitter 2100 in accordance with anotherembodiment. In this embodiment, the pre-coding operation is applied tonot only the E-DPCCH and the E-DPDCH but also to the HS-DPCCH afterspreading operations. The transmitter 2100 comprises physical layerprocessing blocks 2002 for E-DPDCH, spreading blocks 2104, 2106, 2108,2118, combining blocks 2110, 2112, 2120, a precoder 2114, a weightsselection block 2116, scramblers 2122, filters 2124, and antennas 2126.

Primary and secondary E-DCH transport blocks, if dual-stream isconfigured, (or a primary E-DCH transport block if one stream isconfigured), are processed by the physical layer processing blocks 2102for E-DCH. The physical layer processing may include adding CRC paritybits to the transport block, code block segmentation, channel coding,physical layer HARQ, rate matching, physical channel segmentation,interleaving and mapping to E-DPDCH1 and E-DPDCH2 if dual-stream isconfigured, respectively, (or to E-DPDCH1 if a single stream isconfigured). Either E-DPDCH1 or E-DPDCH2 may comprise one or moreE-DPDCHs depending on the E-TFCI selected for the transport block, whichmay or may not be the same, (i.e., the primary transport block may bemapped to one or more E-DPDCHs in E-DPDCH1 and the secondary transportblock may be mapped to one or more E-DPDCHs in E-DPDCH2).

After the physical layer processing, the spreading blocks 2104 performspreading operation on the E-DPDCH1 and E-DPDCH2. Spreading operation onthe E-DPCCH1 and E-DPCCH2, after physical layer processing, is performedby the spreading blocks 2106. Spreading operation on the HS-DPCCH, afterphysical layer processing, is also performed by the spreading block2108. After the spreading operation, the real-valued chips on the I andQ branches of the E-DPDCH(s), the E-DPCCH(s), and the HS-DPCCH aresummed by the combiners 2110, 2112 into two complex-valued streams. Thetwo complex-valued streams are then processed by the pre-coder 2114. Thepre-coder 2114 applies pre-coding weights determined by the weightsselection block 2116 to distribute the signals to the antennas 2126.

DPCCH(s) and DPDCH(s) are spread by the spreading blocks 2118. Thereal-valued chips on the I and Q branches of all the configured physicalchannels, (e.g., DPCCH, DPDCH, HS-DPCCH, E-DPCCH, and E-DPDCH), aresummed by the combiners 2120 into two complex-valued streams, which arethen scrambled by the scramblers 2122 with one or two complex-valuedscrambling codes. The WTRU then transmits data on both antennas afterfiltering. The WTRU may signal the pre-coding weights on the UL, whichwill be explained in detail below.

FIG. 21 shows that the precoding is performed after the spreading andcombining of the E-DPDCH, E-DPCCH, and HS-DPCCH. However, the pre-codingoperation may be performed at any stage, at either symbol or chip level,and may be applied to one or more data or control channels before orafter spreading or scrambling operations depending on the pre-coder'slocation in the transmitter.

This embodiment allows the control channels (including the HS-DPCCH) totake advantage of the additional coverage that pre-coding may provideincluding the single-stream case.

The precoding weights applied to the E-DPCCH and the HS-DPCCH in case ofa single E-DPDCH stream being transmitted may be different from thosewhen two E-DPDCH streams are being transmitted, since weight generationfor diversity may be different from the one for spatial-multiplexing.When there is one E-DPDCH stream, it may share the same precodingweights as E-DPCCH and HS-DPCCH.

FIG. 22 shows an example transmitter 2200 in accordance with anotherembodiment. In this embodiment, the pre-coding is applied to theE-DPDCH(s) before spreading operations, (i.e., at the symbol level). Theprocessing power for pre-coding operation may be saved as it is lesscomputationally intensive to apply the weights at the symbol levelrather than at the chip level.

The transmitter 2200 comprises physical layer processing blocks 2202 forE-DPDCH, a precoder 2204, a weights selection block 2206, spreadingblocks 2208, 2210, 2214, combining blocks 2212, 2216, scramblers 2218,filters 2220, and antennas 2222. Primary and secondary E-DCH transportblocks, if dual-stream is configured, (or a primary E-DCH transportblock if one stream is configured), are processed by the physical layerprocessing blocks 2202 for E-DCH. The physical layer processing mayinclude adding CRC parity bits to the transport block, code blocksegmentation, channel coding, physical layer HARQ, rate matching,physical channel segmentation, interleaving and mapping to E-DPDCH1 andE-DPDCH2 if dual-stream is configured, respectively, (or to E-DPDCH1 ifa single stream is configured).

After the physical layer processing, the data streams, on the E-DPDCH1and E-DPDCH2 are processed by the precoder 2204 at symbol level, (i.e.,before spreading). The pre-coder 2204 applies pre-coding weightsdetermined by the weights selection block 2206 to distribute the signalsto the antennas 2222. Depending on the number of transport blocksscheduled for transmission, the weights selection block 2206 may provideone or more sets of pre-coder weights.

After the precoding, the data streams are spread by the spreading blocks2208. Spreading operation on the E-DPCCH1 and the E-DPCCH2, and allother physical channels is performed by the spreading blocks 2210, 2214,respectively. After the spreading operation on the E-DPDCH(s),E-DPCCH(s) and all other configured physical channels, the chips on theI and Q branches of all the configured physical channels, (e.g., DPCCH,DPDCH, HS-DPCCH, E-DPCCH, and E-DPDCH), are summed by the combiners2212, 2216 into two complex-valued streams, which are then scrambled bythe scramblers 2218 with one or two complex-valued scrambling codes. TheWTRU then transmits data on both antennas 2222 after filtering.

FIG. 23 shows an example transmitter 2300 in accordance with anotherembodiment. In accordance with this embodiment, the pre-coding operationis applied to all channels including both control and data channelsafter scrambling operations. The transmitter 2300 comprises physicallayer processing blocks 2302 for E-DPDCH, spreading blocks 2304, 2306,2308, combining blocks 2310, 2312, scramblers 2314, a precoder 2316, aweights selection block 2318, filters 2320, and antennas 2322. Primaryand secondary E-DCH transport blocks, if dual-stream is configured, (ora primary E-DCH transport block if one stream is configured), areprocessed by the physical layer processing blocks 2302 for E-DCH. Thephysical layer processing may include adding CRC parity bits to thetransport block, code block segmentation, channel coding, physical layerHARQ, rate matching, physical channel segmentation, interleaving andmapping to E-DPDCH1 and E-DPDCH2 if dual-stream is configured,respectively, (or to E-DPDCH1 if a single stream is configured).

After the physical layer processing, the data streams on the E-DPDCH1and E-DPDCH2 are spread by the spreading blocks 2304. Spreadingoperation on the E-DPCCH1 and the E-DPCCH2, and all other physicalchannels is performed by the spreading blocks 2306, 2308, respectively.After the spreading operation on the E-DPDCH(s), E-DPCCH(s) and allother configured physical channels, the chips on the I and Q branches ofall the configured physical channels, (e.g., DPCCH, DPDCH, HS-DPCCH,E-DPCCH, and E-DPDCH), are summed by the combiners 2310, 2312 into twocomplex-valued streams, which are then scrambled by the scramblers 2314with one or two complex-valued scrambling codes.

After the scrambling operation, the pre-coding operation is performed bythe precoder 2316 on the combined data stream of all channels. Thepre-coder 2316 applies pre-coding weights determined by the weightsselection block 2318 to distribute the signals to the antennas 2322.Depending on the number of transport blocks scheduled for transmission,the weights selection block 2318 may provide one or more sets ofpre-coder weights. The transmitter 2300 then transmits data on bothantennas after filtering.

Two different scrambling codes may be used for the two antennas.Alternatively, a single scrambling code may be used for the antennas. Iftwo different scrambling codes are configured by the network, the sameorthogonal variable spreading factor (OVSF) codes, (i.e., thechannelization codes), used on the DPCCH, DPDCH and E-DPCCH for theprimary stream may be reused for those for the secondary stream if thedual-stream is configured with different modulation and coding scheme(MCS). Furthermore, if a dual-stream is configured, the OVSF codes usedfor the primary stream may be reused for the secondary stream undercertain conditions including, but not limited to: if both streams usethe same transport format, if both stream use the same MCS, and/or ifboth stream use the same E-TFCI. Otherwise, the WTRU may use a differentset of channelization code(s) for the second stream. The channelizationcode(s) for the second set of E-DPDCHs may be taken from a differentOVSF branch altogether, selected in such a way to minimize inter-streaminterference and/or cubic metric impacts.

With two different scrambling codes, from the network or the Node-Bperspective, the two streams may be interpreted as if they were comingfrom two different WTRUs. From an implementation perspective, this mayallow minimal changes in the Node-Bs receiver architecture (as small asa software upgrade) and at the system level may not impact the resourcesallocation and cell planning so much as the uplink is not typicallylimited by the number of scrambling codes but rather from theinterference. With the special case of a diagonal precoder,

$( {{e.g.},\begin{bmatrix}1 & 0 \\0 & 1\end{bmatrix}} ),$

this transmitter structure from the physical layer perspective becomesalmost equivalent to having two separate WTRUs. This may be advantageousfrom both the Node-B and the WTRU implementation perspective as it wouldsimplify implementation significantly.

FIG. 24 shows an example transmitter 2400 in accordance with anotherembodiment. In accordance with this embodiment, the pre-coding operationis applied to all channels including both control and data channelsbefore scrambling operations. Optionally, pre-coding operation may bedone before scrambling operations, which is mathematically equal whenusing the same scrambling. The transmitter 2400 comprises physical layerprocessing blocks 2402 for E-DPDCH, spreading blocks 2404, 2406, 2408,combining blocks 2410, 2412, a precoder 2414, a weights selection block2416, scramblers 2418, filters 2420, and antennas 2422. Primary andsecondary E-DCH transport blocks, if dual-stream is configured, (or aprimary E-DCH transport block if one stream is configured), areprocessed by the physical layer processing blocks 2402 for E-DCH. Thephysical layer processing may include adding CRC parity bits to thetransport block, code block segmentation, channel coding, physical layerHARQ, rate matching, physical channel segmentation, interleaving andmapping to E-DPDCH1 and E-DPDCH2 if dual-stream is configured,respectively, (or to E-DPDCH1 if a single stream is configured).

After the physical layer processing, the data streams on the E-DPDCH1and E-DPDCH2 are spread by the spreading blocks 2404. Spreadingoperation on the E-DPCCH1 and/or the E-DPCCH2, and all other physicalchannels is performed by the spreading blocks 2406, 2408, respectively.After the spreading operation on the E-DPDCH(s), E-DPCCH(s) and allother configured physical channels, the chips on the I and Q branches ofall the configured physical channels, (e.g., DPCCH, DPDCH, HS-DPCCH,E-DPCCH, and E-DPDCH), are summed by the combiners 2410, 2412 into twocomplex-valued streams.

A pre-coding operation is then performed by the precoder 2414 on thecombined two complex data streams of all channels. The pre-coder 2414applies pre-coding weights determined by the weights selection block2416 to distribute the signals to the antennas 2422. Depending on thenumber of transport blocks scheduled for transmission, the weightsselection block 2416 may provide one or more sets of pre-coder weights.After the precoding, the data streams are scrambled by the scramblers2418 with one or two complex-valued scrambling codes. The transmitter2400 then transmits data on both antennas 2422 after filtering.

When two different scrambling codes are used for both antennas,separation of each stream may be achieved via scrambling code in thetransmitter of FIG. 23, whereas per-antenna separation may be achievedvia scrambling code in the transmitter of FIG. 24. Having a means toseparate the signals at the antenna may be advantageous for channelestimation when the DPCCH is pre-coded, as is the case in thisembodiment.

In accordance with this embodiment, the Node-B receiver may separatesignals based on antenna, and even if the pilot signals are pre-coded,the channel matrix may be estimated correctly so that the Node-B maydetermine which set of precoding weights to signal to the WTRU. Inaccordance with this embodiment, the effective space-time channel foreach stream may be estimated with a single DPCCH for detection, and thechannel matrix may be estimated by separating via scrambling codes. Thisstructure also has an advantage that for single stream transmission,minimum or no change on the receiver side is needed. This may havesignificant advantage for reducing implementation cost for certaintechnologies which are widely deployed such as UTRA.

FIG. 25 shows an example transmitter 2500 in accordance with anotherembodiment. The transmitter 2500 is similar to the transmitter 2100 ofFIG. 21. A difference is that pre-coding is also applied to DPDCH, ifconfigured, after spreading operations. This allows the DPDCHs tobenefit from pre-coding and the closed loop transmit gain that mayresult. In other words, transmitter 2500 applies pre-coding to allconfigured channels except DPCCH1 and DPCCH2.

Transmitted signal structure and spreading operations are explainedhereafter. For any transmitter embodiments described above, thetransmitted signal, (i.e., the possible dedicated physical channelswhich may be configured simultaneously for a WTRU), may comprise one ormore of, in any combination: DPCCH1, DPCCH2, DPDCH1, DPDCH2, HS-DPCCH,E-DPDCH1, E-DPDCH2, E-DPCCH1, and/or E-DPCCH2. DPCCH1 and DPCCH2 aretransmitted using OVSF code Cc1 and Cc2, respectively, to supportchannel estimation at the Node-B by using pilot signal and carry thecontrol information. If pilot signal (at the symbol level) in DPCCH1 andDPCCH2 are orthogonal, the OVSF code Cc1 and Cc2 may be the same. If thesame pilot signal is used in both DPCCH1 and DPCCH2, the OVSF code Cc1and Cc2 should be orthogonal. Both DPCCH1 and DPCCH2 may be transmittedin pair unless during the period where the UL transmission is notallowed, for example, when the WTRU is in DTX or compressed mode.

The control information carried on the DPCCH1 may include transportformat combination index (TFCI), feedback information (FBI) and transmitpower control (TPC). The DPCCH2 may carry a pilot signal. Alternatively,the DPCCH2 may carry another set of control information besides thepilot signal, which may include part or all of the control informationcarried on the DPCCH1, and/or other new control information, such aspre-coding weight, etc.

Depending on the number of DPDCH data streams being transmitted, one ortwo set of DPDCH(s) may be transmitted on two antennas. Two sets ofDPDCH, (i.e. DPDCH1 and DPDCH2), may be respectively transmitted byusing OVSF code set Cd1 and Cd2. Either DPDCH1 or DPDCH2 may comprisezero, one or more DPDCHs which may or may not be the same. The actualnumber of configured DPDCHs in DPDCH1 and DPDCH2, (denotedN_(max-dpdch1) and N_(max-dpdch2)), may be respectively equal to thelargest number of DPDCHs from all the transport format combinations(TFCs) in the transport format combination set (TFCS). Alternatively,neither DPDCH1 nor DPDCH2 may be transmitted when no DPDCH data streamis configured. Alternatively, DPDCH1 may be transmitted using OVSF codeset Cd1 when a single DCH data stream is configured. To maintain thebackward compatibility to 3GPP Release 9, when an E-DCH is configured,either N_(max-dpdch1) or N_(max-dpdch2) may be 0 or 1, or N_(max-dpdch1)may be 0 or 1 while N_(max-doch2) is 0.

The HS-DPCCH may be transmitted using OVSF code Chs to carry HARQACK/NACK, channel quality indicator (CQI) and precoding indicator (PCI)if the WTRU is in a downlink (DL) MIMO mode.

The E-DPCCH1 and E-DPCCH2 may be respectively transmitted using OVSFcode Cec1 and Cec2 to provide the control information to the associatedthe E-DCH. For a single stream case, the E-DPCCH1 may be transmitted.Alternatively, a single E-DPCCH may be used to carry the information forboth streams, in which case Cec1 may be used.

A new E-DPCCH frame/slot format and/or coding scheme may be used tocarry all the necessary information. In accordance with one embodiment,a new slot format allowing more information symbols to be carried in asingle TTI is used. For example, the new slot format may use a smallerspreading factor, (e.g., 128 instead of 256), to allow twice the numberof information symbols to be carried in one TTI of the E-DPCCH. In thatcase, the conventional coding scheme for the E-DPCCH may be re-used foreach stream independently.

In accordance with another embodiment, time-division multiplexing may beused to transmit the two E-DPCCHs. For instance, E-DPCCH1 and E-DPCCH2may be carried in the first and second half of the TTI, respectively.Another field may be included in the E-DPCCH1 and/or E-DPCCH2 toindicate the number of streams transmitted in the current TTI. In case asingle stream is being transmitted, the E-DPCCH1 may be repeated in thesecond half of the subframe. In such cases, when E-DPCCH power boostingis configured, the WTRU may calculate the required power boosting foreach E-DPCCH and apply the largest one of the two for both E-DPCCHs thatare time-multiplexed in the same E-DPCCH subframe.

In accordance with another embodiment, a new coding scheme may be usedwhereby the information for both E-DCH streams is jointly encoded in asingle E-DPCCH. A new field may be introduced in the new E-DPCCH toindicate the number of streams carried in the TTI. This new E-DPCCH maycarry, for example, a number of streams indicator bit, a single “Happybit” value, one E-TFCI per stream and one retransmission sequence number(RSN) per stream for up to 20 bits of information. This new E-DPCCH maybe carried using the conventional slot format with spreading factor of256 or alternatively using a lower spreading factor. This new E-DPCCHmay be encoded using an existing code or a new code, (e.g., a new (30,20) code for the case where SF 256 is used, or a new (60,20) code incase SF of 128 is used). The WTRU may apply a larger power offset to theE-DPCCH when two streams are being transmitted to ensure reliablereception. When a single stream is transmitted, the fields carrying theE-TFCI and the RSN for the second stream may be DTXed.

Depending on the number of streams to be transmitted, one or two set,(i.e., multiple codes), of E-DPDCH may be transmitted. For dual-streamcase where the WTRU performs the E-TFC selection, which results in twotransport blocks to be transmitted and the WTRU applies the OVSFconfiguration corresponding to dual stream transmission and transmitsthe dual streams, the E-DPDCH1 and the E-DPDCH2 may be respectivelytransmitted using OVSF code set Ced1 and Ced2. Either E-DPDCH1 orE-DPDCH2 may comprise one or more E-DPDCHs depending on the E-TFCIselected for either primary or secondary E-DCH transport block, whichmay or may not be of the same size. In the dual stream case, each E-DCHtransport block may have a different size or E-TFCI, so thechannelization code set Ced1 and Ced2 may or may not be different.Alternatively, for a single stream case where one transport block ofE-DCH is scheduled, the E-DPDCH1 may be transmitted by using OVSF codeset Ced1 which may be, for example, the conventional OVSF code set usedfor single carrier HSUPA without MIMO configured.

If the spreading factor determination results in two differentchannelization codes Ced1 and Ced2 for the E-DPDCH1 and E-DPDCH2,respectively, to ensure the mathematical or functional equivalencebetween the case of precoding in symbol level before spreading and thecase of precoding in chip level after spreading, Ced1, Ced2 may bechosen such that one of them may be the repetition of the other.

When the WTRU is configured in a closed-loop transmit diversity (CLTD)mode or a single stream MIMO mode, neither E-DPDCH2 nor E-DPCCH2 may beconfigured or transmitted. More specifically, when a single E-DCH streamis being transmitted, the second set of E-DCH data and control channelsmay not be transmitted by the WTRU.

The DPCCH2 may be mapped to I or Q branch. In order to select the bestchannelization code for the DPCCH2, first, the available channelizationcode space is searched for the DPCCH2 by not selecting the code used byother channels on either I or Q branches to reduce the phase errorduring channel estimation. Depending on whether a DCH is configured ornot, the available channelization code space obtained in the first stepmay be different. Among the available code space, the bestchannelization code is selected to obtain a smaller cubic metric (CM)value than other codes given a transmitter structure and configuration.For example, when using the transmitter 2400 with a CLTD modeconfiguration, if the DPCCH2 is configured on an I branch, thechannelization code of the DPCCH2 may be selected as C_(ch,256,32), andif the DPCCH2 is configured on a Q branch, the channelization code ofthe DPCCH2 may be selected as C_(ch,256,2).

The OVSF codes Cc1, Cc2, Cd1, Cd2, Chs, Cec1, Cec2, Ced1, and Ced2 maybe fixed in the standards or configured by the network.

FIG. 26 shows the spreading operation, which includes spreading with agiven channelization code, weighting, and IQ phase mapping. Thespreading operation is applied to every physical channel. The spreadingoperation may be represented by:

SF _(—) CH=CH*C _(CH) *β _(CH) *iq _(CH),   Equation (5)

where, CH is the real-valued bits of the physical channel to be spreadand weighted, C_(CH) is the OVSF channelization code fixed in thestandards or configured by the network, β_(CH) is a gain factor that maybe signaled or calculated based on the signaled parameters and thetransport block size or number of information bits, iq_(CH) is a complexvalue for the I or Q branch mapping, where iq_(CH)=1 or iq_(CH)=j.

After spreading operation, the streams of real-valued chips on I and Qbranches are summed into two complex-valued streams which are thenscrambled by one or two complex-valued scrambling codes configured bythe network. The operation is carried out as follows: the WTRU receivesa configuration message carrying scrambling code information. The WTRUapplies the scrambling code to the complex-valued streams. Scramblingmay be carried out after the spreading operation for each channelseparately, after the spread channels are all summed together, or aftersumming of all non-precoded and pre-coded channels as shown in differenttransmitter embodiments described above. Optionally, the WTRU may applythe pre-coding weights to two complex scrambled streams if transmitter2300 is used. The WTRU then transmits data on both antennas afterfiltering with transmit pulse, (e.g., a root raised-cosine filter).

Pre-coding operations are explained hereafter. FIG. 27 shows an examplepre-coder for the dual stream case. The precoding operation may berepresented as follows:

$\begin{matrix}{\begin{matrix}{\begin{bmatrix}B_{p} \\B_{s}\end{bmatrix} = {W\begin{bmatrix}A_{p} \\A_{s}\end{bmatrix}}} \\{= {\begin{bmatrix}w_{1} & w_{3} \\w_{2} & w_{4}\end{bmatrix}\begin{bmatrix}A_{p} \\A_{s}\end{bmatrix}}} \\{{= \begin{bmatrix}{{w_{1}A_{p}} + {w_{3}A_{s}}} \\{{w_{2}A_{p}} + {w_{4}A_{s}}}\end{bmatrix}},}\end{matrix}{{{where}\mspace{14mu} W} = \begin{bmatrix}w_{1} & w_{3} \\w_{2} & w_{4}\end{bmatrix}}} & {{Equation}\mspace{14mu} (6)}\end{matrix}$

is the pre-coding matrix. A_(p) and A_(s) may be complex or real values.After applying the pre-coding operation, A_(p) and A_(s) are distributedon the first and second transmit antenna, which are represented byB_(p)=w₁A_(p)+w₃A_(s) and B_(s)=w₂A_(p)+w_(A)A_(s), respectively.

When A_(s)=0, (i.e., a single stream case), B_(p)=w₁A_(p) andB_(s)=w₂A_(p) are respectively sent on the first and second antenna.

FIG. 28 shows another example pre-coder for the dual stream case. InHSUPA, real-valued I/Q branches are separated before I/Q multiplexing.The pre-coding operation is applied to the I and Q branches of each ofthe primary and secondary streams A_(p) and A_(q), respectively, thenI/Q multiplexing is performed on the pre-coded I/Q branch data. Inaccordance with this embodiment, the I/Q branches are processed inparallel, reducing the implementation complexity. Mathematically, theoutputs of the two pre-coders are the same given the same input, whichmay be represented as follows:

$\begin{matrix}\begin{matrix}{\begin{bmatrix}B_{p} \\B_{s}\end{bmatrix} = {W\begin{bmatrix}A_{p} \\A_{s}\end{bmatrix}}} \\{= {\begin{bmatrix}w_{1} & w_{3} \\w_{2} & w_{4}\end{bmatrix}\begin{bmatrix}{A_{p,I} + {j\; A_{p,Q}}} \\{A_{s,I} + {j\; A_{s,Q}}}\end{bmatrix}}} \\{= {\begin{bmatrix}w_{1} & w_{3} \\w_{2} & w_{4}\end{bmatrix}( {\begin{bmatrix}A_{p,I} \\A_{s,I}\end{bmatrix} + {j\begin{bmatrix}A_{p,Q} \\A_{s,Q}\end{bmatrix}}} )}} \\{= {{\begin{bmatrix}w_{1} & w_{3} \\w_{2} & w_{4}\end{bmatrix}\begin{bmatrix}A_{p,I} \\A_{s,I}\end{bmatrix}} + {{j\begin{bmatrix}w_{1} & w_{3} \\w_{2} & w_{4}\end{bmatrix}}\begin{bmatrix}A_{p,Q} \\A_{s,Q}\end{bmatrix}}}}\end{matrix} & {{Equation}\mspace{14mu} (7)}\end{matrix}$

where A_(p)=A_(p,I)+jA_(pQ), A_(s)=A_(s,I)+jA_(s,Q), and A_(p,i) andA_(s,I) are the real part (I branch) of the complex-valued A_(p) andA_(s), A_(p,Q) and A_(s,Q) are the image part (Q branch) of thecomplex-valued A_(p) and A_(s). The above two pre-coder embodiments maybe used for one or more physical channels, and may be used incombination with any transmitter structures described herein.

In order to save on computing complexity, the pre-coding may beperformed at the symbol level as opposed to the chip level. For these tobe equivalent, the channelization codes (or spreading codes), gainfactor and I/Q mapping need to be the same for both channels topre-code, or the precoding weight matrix W is diagonal.

FIG. 29 shows another example pre-coder for the dual stream case. If thetwo streams use different spreading factors, for thepre-coding-before-spreading be equivalent to thespreading-before-pre-coding the spreading code of the highest data ratechannel needs to be constructed from a repetition of the spreading codefor the lowest data rate channel. For example, assuming two channelswith spreading factors 2 and 4 are being transmitted. If thechannelization code for the channel with a spreading factor 2 is Cch2=[1−1], the channelization code for the channel with a spreading factor 4may be C_(ch1)=[Cch2 Cch2]=[1 −1 1 −1].

In FIG. 29, the precoding is applied before spreading and two datastreams C_(s) and C_(p) (assuming C_(ed1) and C_(ed2) are OVSF codes fordata streams C_(s) and C_(p), respectively) use OVSFs with differentspreading factors SF_(ed1) and S_(Fed2) with SF_(ed2)=N×SF_(ed1). Thedata stream with the lowest (or lower) symbol rate (C_(s)) is weightedand repeated N times before mixed with the other stream (C_(p)) that isweighted. At the output of the precoder, both streams D_(s) and D_(p)are spread with the channelization code of the smallest spreading factorof SF_(ed1) and SF_(ed2) (C_(ed1) in this example).

The above embodiment may be applied for example to the E-DCHtransmission with four E-DPDCHs. FIG. 30 shows an example transmitterfor the two stream case. For applying pre-coding before spreading, thechannels are grouped first with respect to their spreading factor,(i.e., channels of the same spreading factors are grouped together), andthe data streams are pre-coded and then spread.

E-DPDCH_(k) ^((l)) is defined as the k^(th) E-DPDCH for the l^(th)stream. Four E-DPDCHs are used for each of the two data streams. Foreach stream, the first and second E-DPDCHs are spread using the samechannelization code of the same spreading factor, (e.g., 2), and thefirst E-DPDCH is mapped on the I branch and the second E-DPDCH is mappedon the Q branch, and the third and fourth E-DPDCHs are spread using thesame channelization code of the same spreading factor, (e.g., 4), andthe third E-DPDCH is mapped on the I branch and the fourth E-DPDCH ismapped on the Q branch. In FIG. 30, the first and second E-DPDCHs of thefirst stream are combined by a combiner 3002 into a complex signal, andthe first and second E-DPDCHs of the second stream are combined by acombiner 3004 into a complex signal and then pre-coded by a pre-coder3010, and the third and fourth E-DPDCHs of the first stream are combinedby a combiner 3006 into a complex signal, and the third and fourthE-DPDCHs of the second stream are combined by a combiner 3008 into acomplex signal and then pre-coded by a pre-coder 3012. After thepre-coding, the first and second E-DPDCHs of the two streams are spreadby channelization blocks 3014, 3016 with a channelization code of thesame spreading factor, (in this example, a channelization code ofspreading factor 2 (C_(ch,2,1))), and the third and fourth E-DPDCHs ofthe two streams are spread by channelization blocks 3018, 3020 with achannelization of the same spreading factor, (in this example, achannelization code of spreading factor 4 (C_(ch,4,1))). Afterspreading, the antenna components are combined by the combiners 3022,3024 for transmission.

Other combination of pairs of E-DCHs may also be implemented. Up to twoE-DPDCHs from the same stream mapped on different I/Q branches may becombined together for pre-coding. The inputs to the pre-coder maycomprise two complex signals from each stream. If the spreading factorfor all inputs to the pre-coder is the same, the channelization codesfor input channels to the same pre-coder may be the same. If all inputsto the pre-coder do not have the same data rate or spreading factor, thelower data rate input(s) may be repeated for matching the highest datarate input.

A combination of the approaches illustrated in FIG. 28 and FIG. 29 maybe used to optimize the computational complexity of applying theprecoding operation.

It is further noted that the embodiments illustrated in FIGS. 28-30 mayalso be used to other pair of channels besides the E-DPDCH when thespreading code properties permits.

Embodiments for generating pre-coding weights are described. Thepre-coding weights matrix W may be chosen from a set of pre-codermatrices, (i.e., codebook), or be determined without a codebook.

If codebook-based pre-coding is used, unitary matrices may be used asthe pre-defined pre-coder matrix. One example codebook is as follows:

$W \in {\begin{Bmatrix}{{\frac{1}{\sqrt{2}}\begin{bmatrix}1 & 1 \\1 & {- 1}\end{bmatrix}},{\frac{1}{\sqrt{2}}\begin{bmatrix}1 & 1 \\j & {- j}\end{bmatrix}},} \\{\begin{bmatrix}\frac{1}{\sqrt{2}} & \frac{1}{\sqrt{2}} \\\frac{1 + j}{2} & \frac{{- 1} - j}{2}\end{bmatrix},\begin{bmatrix}\frac{1}{\sqrt{2}} & \frac{1}{\sqrt{2}} \\\frac{1 + j}{2} & \frac{{- 1} + j}{2}\end{bmatrix},\begin{bmatrix}1 & 0 \\0 & 1\end{bmatrix}}\end{Bmatrix}.}$

DL MIMO pre-coding matrix may be reused for the UL MIMO, whose weightsw₁, w₂, w₃ and w₄ of the 2×2 pre-coding matrix are defined as follows:

$\begin{matrix}{{w_{3} = {w_{1} = {1/\sqrt{2}}}},} & {{Equation}\mspace{14mu} (8)} \\{{w_{4} = {- w_{2}}},} & {{Equation}\mspace{14mu} (9)} \\{w_{2} \in {\{ {\frac{1 + j}{2},\frac{1 - j}{2},\frac{{- 1} + j}{2},\frac{{- 1} - j}{2}} \}.}} & {{Equation}\mspace{14mu} (10)}\end{matrix}$

If a single transport block is scheduled in one TTI, the pre-codingvector (w₁, w₂) may be used for transmission. If two transport blocksare scheduled in one TTI, two orthogonal pre-coding vectors may be usedto transmit the two transport blocks. The pre-coding vector (w₁, w₂) maybe called the primary pre-coding vector which is used for transmittingthe primary transport block and the pre-coding vector (w₃, w₄) may becalled the secondary pre-coding vector which is used for transmittingthe secondary transport block, respectively.

If non-codebook-based pre-coding is used, the pre-coding may be based ontransmit beamforming (TxBF), for example, eigen-beamforming based onsingular value decomposition (SVD). For pre-coding usingeigen-beamforming, the channel matrix H is decomposed using an SVD,(i.e., a pre-coding matrix W is a unitary matrix chosen such thatH=UΣW^(H). The eigen-channel's signal-to-noise ratio (SNR) may bematched by selecting a suitable modulation and coding scheme (MCS) foreach stream.

Generally, non-codebook-based pre-coding schemes give the betterperformance and more freedom to the size of the codebook thancodebook-based pre-coding at the cost of feedback signaling overhead inthe DL and potential control signaling overhead in the UL.

The special case of the identity matrix

$( \begin{bmatrix}1 & 0 \\0 & 1\end{bmatrix} )\quad$

as a pre-coding codebook is equivalent for certain transmitterstructures in single stream operations to a switch antennas transmitter(thereby using switch antenna transmit diversity (SATD)). For example,this is the case for transmitter 2100 and 2500 and also 2300 and 2400when the same scrambling code is used.

Embodiments for selecting and signaling the pre-coding weights areexplained hereafter.

When channel-dependent MIMO schemes are used for HSUPA,channel-dependent information may be sent from a Node-B to a WTRU forpre-coding operation. This information allows the WTRU to adjust thepre-coding weights as a function of the channel propagation conditions.For example, this channel-dependent feedback information may compriseuplink pre-coding control indication (UPCI), channel state information(CSI), or CSI-related information (such as serving grants carried on anE-DCH absolute grant channel (E-AGCH), an E-DCH relative grant channel(E-RGCH) or TPC commands carried on DL DPCCH/F-DPCCH, etc.).

A Node-B may determine a set of pre-coding weights, and indicate it tothe WTRU. For example, the set of pre-coding weights may be indicated tothe WTRU via a control signal carrying uplink pre-coding controlinformation (UPCI).

The UPCI may be transmitted by the Node-B using an E-DCH HARQ indicatorchannel (E-HICH) and an E-RGCH. The E-HICH and E-RGCH are both currentlyusing a similar structure. Forty (40) signatures are defined with fortysequences which comprise a pre-defined signature hopping pattern over 3radio slots. For normal operations, the network assigns one sequence perE-HICH or E-RGCH which are modulated by values +1, −1 or 0 (DTX) by theNode-B. In one implementation of UPCI signaling (which applies to bothE-HICH and E-RGCH), the WTRU may receive the UPCI through a variation ofthis E-HICH/E-RGCH structure.

FIG. 31A shows an example UPCI signaling using an E-HICH. In thisembodiment, a WTRU may be configured to listen to a specific E-HICHchannelization code from, for example, an E-DCH serving cell. As shownin FIG. 31A, the first radio slot 3102 of the E-HICH subframe carriesthe conventional E-HICH signal while the subsequent two radio slots 3104of the E-HICH subframe carry the signaling for the UPCI. Alternatively,the first two radio slots of the E-HICH subframe may carry the E-HICHsignal while the last radio slot of the E-HICH subframe carry thesignaling for the UPCI. Any other variations are also possible. Thisembodiment allows the network to save on channelization code space, atthe expense of additional transmission power to maintain similarreliability level for the E-HICH. The same approach may also be used forthe E-RGCH.

The WTRU may be configured to listen to the UPCI periodically, with acertain configured or pre-defined period. In case where the WTRU is notconfigured to listen to the UPCI, the conventional three radio slots ofthe E-HICH subframe may carry the conventional E-HICH information (ifpresent). This allows reducing the amount of downlink signaling forsupport of UL MIMO operations. The same approach may also be used forthe E-RGCH. FIG. 31B illustrates the case where one out of seven E-HICHsubframes carries the UPCI field. Even if the Node-B has no ACK/NACK totransmit during those periods, the UPCI field may be transmitted.

In accordance with another embodiment, a new set of orthogonal signaturesequences may be used to signal the UPCI via the E-HICH, the E-GRCH, ora different channel. The new signature sequences may or may not be usedin combination with the signature hopping pattern of the E-HICH or theE-RGCH. For example, the new sequences may be modulated by +1, −1 by theUPCI information bits.

To carry more than one information bit, multiple sequences may be used.Alternatively, the information bits may modulate a given radio slot inthe three slots sequence. For example, the first half of the sub-framemay be modulated by the first information bit of the UPCI, (e.g., a mostsignificant bit (MSB)), while the second half may be modulated by thesecond information bit of the UPCI, (e.g., a least significant bit(LSB)). Alternatively, in case two UPCI information bits need to betransmitted, two of the three radio slots may be used to transmit theinformation and the remaining radio slot of the subframe may be DTXed.The radio slots for the UPCI information may not be consecutive, (e.g.,the first and third radio slots may be used for the UPCI information andthe second radio slot may be DTXed).

The signature sequences may be received by the WTRU at the same time asthe conventional sequences over a channelization code that is orthogonalto the one used by the E-HICH/E-RGCH. The WTRU may be configured by thenetwork to monitor one or more such new sequences on one or moreE-HICH/E-RGCH. Alternatively, the WTRU may be configured to monitorthese sequences for a specific instant of time, (e.g., periodically).This may allow the network to save on transmission power.

In accordance with another embodiment, the WTRU may be configured by thenetwork, in addition to the conventional E-HICH/E-RGCH set, to monitor adedicated set of E-HICH/E-RGCH conventional sequences that carry theUPCI information.

In accordance with another embodiment, a new feedback channel, (will hereferred to as “E-DCH channel stated information channel (E-CSICH)”) maybe defined to signal the UPCI. In order to have a minimum impact onlegacy E-HICH/E-RGCH channels, a new type of dedicated downlink feedbackchannel E-CSICH may be defined, where a channelization code differentfrom the one used by the E-HICH/E-RGCH is used. The E-CSICH may use anorthogonal signature sequence as in the E-HICH/E-RGCH as a means toallow multiple users sharing the same channelization code and codemultiplexing of UPCI bits for a specific WTRU. The signature sequencesmay comprise a set of orthogonal sequences with a length equal to oneslot of the subframe and the sequence may be repeated over multipleslots of the subframe up to the duration of the E-CSICH.

Without loss of generality, in the following E-CSICH examples, two WTRUsin a cell, each having 2-bit UPCI information, are assumed as anexample.

FIG. 32 shows an example transmitter 3200 for transmitting UPCI for twoWTRUs via an E-CSICH in accordance with one embodiment. The transmitter3200 includes UPCI mappers 3202, mixers 3204, repeaters 3206, a combiner3208, and a channelization unit 3210. The two bits of UPCI for each WTRUare mapped to a certain value by the UPCI mapper 3202, respectively. Thetwo UPCI bits may be generated once per TTI, (i.e., one output per 2 msTTI). An example mapping of the two bit UPCI to a complex value is shownin Table 3. The mapped value of each WTRU is modulated with a differentM-bit long orthogonal sequence by the mixer 3204, and then repeated overN times by the repeater 3206, where N may be 1 or higher integer. Theresulting data for the two WTRUs are combined by the combiner 3208 andspread with a channelization code by the channelization unit 3210. Withthis embodiment, different WTRUs may share the same E-CSICH by usingdifferent orthogonal sequences.

TABLE 3 UPCI value Output of UPCI (decimal/binary) mapper 0/00  1 + j1/01 −1 + j 2/10  1 − j 3/11 −1 − j

FIG. 33 shows another example transmitter 3300 for transmitting UPCI fortwo WTRUs via an E-CSICH in accordance with another embodiment. In thisembodiment, the UPCI information bits of a specific WTRU istime-multiplexed and E-CSICHs for different WTRUs are code-multiplexed.The transmitter 3300 includes mixers 3302, modulation mappers 3304,repeaters 3306, a combiner 3308, and a channelization unit 3310. TheUPCI information bits, (e.g., one bit per slot), for each WTRU aremodulated with a different signature sequence by the mixer 3302,respectively, which generates M bits per slot where M is the length ofthe signature sequence. The binary information bits may be mapped to +1and −1 before applying a signature sequence. In this example, the twoUPCI bits are modulated over two slots. The M bits per slot aremodulated, (e.g., QPSK), by the modulation mapper 3304 and may berepeated over N times by the repeater 3306, where N is 1 or higherinteger. The resulting two data are combined by the combiner 3308 andspread with a channelization code by the channelization unit 3310.

FIG. 34 shows another example transmitter 3400 for transmitting UPCI fortwo WTRUs via an E-CSICH in accordance with another embodiment. In thisembodiment, both UPCI information bits of a specific WTRU and E-CSICHsfor different WTRUs are code-multiplexed. The transmitter 3400 includesmixers 3402, modulation mappers 3404, combiners 3406, 3410, repeaters3408, and a channelization unit 3412. Each of the two UPCI bits for eachWTRU is modulated with a different M-bit long orthogonal sequence by themixer 3402. The binary information bits may be mapped to +1 and −1before applying a signature sequence. The M bits are modulated by themodulation mapper 3404, (e.g., QPSK). The modulated UPCI signals for thesame WTRU are combined by the combiner 3406, and then may be repeatedover N times by the repeater 3408, where N may be 1 or higher integer.The resulting data for the two WTRUs are combined by the combiner 3410and spread with a channelization code by the channelization unit 3412.

For M=40, the legacy 40-bit long signature sequences may be reused forthe orthogonal signature sequences. Alternatively, For M=20, thefollowing twenty 20-bit long sequences may be used as the orthogonalsignature sequences.

$C_{{ss},20} = \begin{bmatrix}A & A & B & C \\{- B} & {- C} & A & A \\{- A} & A & C & {- B} \\{- C} & B & {- A} & A\end{bmatrix}$ where ${A = \begin{bmatrix}{- 1} & 1 & 1 & 1 & 1 \\1 & {- 1} & 1 & 1 & 1 \\1 & 1 & {- 1} & 1 & 1 \\1 & 1 & 1 & {- 1} & 1 \\1 & 1 & 1 & 1 & {- 1}\end{bmatrix}};$ ${B = \begin{bmatrix}1 & {- 1} & 1 & 1 & {- 1} \\{- 1} & 1 & {- 1} & 1 & 1 \\1 & {- 1} & 1 & {- 1} & 1 \\1 & 1 & {- 1} & 1 & {- 1} \\{- 1} & 1 & 1 & {- 1} & 1\end{bmatrix}};$ $C = {\begin{bmatrix}1 & 1 & {- 1} & {- 1} & 1 \\1 & 1 & 1 & {- 1} & {- 1} \\{- 1} & 1 & 1 & 1 & {- 1} \\{- 1} & {- 1} & 1 & 1 & 1 \\1 & {- 1} & {- 1} & 1 & 1\end{bmatrix}.}$

In accordance with another embodiment, the pre-coding weights may beindicated using the E-AGCH. The current 3GPP Release 6 E-AGCH carries upto 6 information bits (5 bits for the absolute grant information and onebit for the absolute grant scope). In accordance with one embodiment, anew E-AGCH structure may be defined to carry the UPCI field in additionto the conventional fields. When a WTRU receives an E-AGCH, the WTRU mayuse the UPCI weights indicated in the E-AGCH until the next E-AGCH (withpotentially different set of UPCI weights to use). This embodimentprovides a solution with a small amount of downlink signaling.

In accordance with another embodiment, the absolute grant field of theE-AGCH may be reduced from 5 bits to a smaller value, (e.g., 3 bits),and the free bits may be used for the UPCI field. This allows thenetwork to use similar power level on the E-AGCH and maintain the samelevel of reliability, at the expense of some granularity on the absolutegrant.

In accordance with another embodiment, the pre-coding weights may beindicated using a high speed shared control channel (HS-SCCH).Currently, an HS-SCCH order may be used for activation and deactivationof DTX, discontinues reception (DRX), and HS-SCCH-less operation, forhigh speed downlink shard channel (HS-DSCH) serving cell changeindication, and for the activation and deactivation of secondary servingHS-DSCH cell and secondary uplink frequency. When associated to a highspeed physical downlink shared channel (HS-PDSCH), the HS-SCCH carriescontrol information for demodulating the HS-PDSCH.

In accordance with one embodiment, the HS-SCCH order may be used tocarry the UPCI by introducing a new HS-SCCH order type. The order bits(3-bits long) of the HS-SCCH may be used to carry the UPCI. For example,any two of the 3 order bits, Xord,1, Xord,2, Xord,3 may indicate 4possible UPCI values. Alternatively, all 3 order bits may be used toindicate up to 8 possible UPCI values to provide fine granularity ofpre-coding weights.

In accordance with another embodiment, as the WTRU needs to monitor upto four HS-SCCHs, the decoded HS-SCCH number may implicitly signal theUPCI. For example, if (the decoded HS-SCCH number) MOD 4=0, 1, 2 and 3may indicate 4 possible UPCI values, respectively. In the case ofmulticarrier high speed downlink packet access (MC-HSDPA) where morethan one downlink carrier is activated simultaneously, the HS-SCCHnumber may refer to the HS-SCCH number carried on the DL carrierassociated with the UL carrier which the signaled UPCI will be appliedto.

In accordance with another embodiment, the HS-SCCH type 1 and 3 physicalchannels may be used to signal the UPCI by using and reinterpreting theunused field of the HS-SCCH. For example, 2 more bits may be freed fromthe channelization code set bits Xces,1, Xces,2, . . . , Xces,7 by onlysignaling P (15 codes need 4 bits) if 0 can be signaled via higherlayer.

When the WTRU receives an HS-SCCH (either HS-SCCH order or HS-SCCHphysical channel), the WTRU may use the UPCI carried in the HS-SCCHuntil the next HS-SCCH (with potentially different set of UPCI weightsto use).

In accordance with another embodiment, the pre-coding weights may beindicated using a fractional dedicated physical channel (F-DPCH). Thecurrent 3GPP Release 9 F-DPCH is designed to carry up to 2 bits of TPCcommand every slot. By assigning a WTRU specific timing offset or slotformat, it is possible to multiplex up to 10 WTRUs onto onechannelization code for F-DPCH.

In accordance with one embodiment, a second F-DPCH may be transmittedwith a different channelization code to signal the UPCI. Given the sametime offset of the F-DPCHs, the two F-DPCHs for the same WTRU may betransmitted with the same or different F-DPCH slot format. For thesecond F-DPCH, the UPCI may be transmitted every slot or every TTI,(e.g., 3 slots). If the UPCI is updated every TTI, the same UPCI may berepeatedly transmitted on 3 consecutive slots, or the updated UPCI maybe transmitted on one of the 3 slots and the unused 2 slots may be DTXedor used for signaling the UPCI or TPC commands for other WTRUs.

Alternatively, given the same F-DPCH slot format, two F-DPCHstransmitted to one WTRU may use the same time offset of the F-DPCH fordetermining the uplink frame time. The two F-DPCHs transmitted to oneWTRU may use the different time offset.

Alternatively, a Node-B may transmit one F-DPCH to a WTRU with adifferent F-DPCH format. FIG. 35 shows an F-DPCH format in accordancewith this embodiment. As shown in FIG. 35, both the TPC field 3502 andthe UPCI field 3504 are transmitted in one F-DPCH. By appropriatelyassigning an F-DPCH slot format, it is possible to time multiplex up to5 WTRUs configured for uplink MIMO or less than 10 WTRUs configured forMIMO or non-MIMO onto one channelization code for F-DPCH.

The appropriate slot format should be configured for different WTRUs tomake sure that there is no overlap between a UPCI field of one WTRU anda TPC field of the other WTRU. For example, 5 odd-numbered slot formatsmay be configured, (i.e., the F-DPCH slot format number=1, 3, 5, 7, 9)to 5 MIMO WTRUs onto one channelization code for the F-DPCH.

Embodiments for the WTRU to select pre-coding weights are disclosedhereafter.

In accordance with one embodiment, a WTRU may select the pre-codingweights based on the received UPCI. The mapping between the pre-codingweights and the UPCI may be pre-defined in the specification. Forexample, the pre-coding weights may be mapped to 4 possible UPCI values,(i.e., w₂ ^(ref)), as shown in Table 4. In Table 4, the first pre-codingweight w₁ ^(pref) of the preferred primary pre-coding vector (w₁^(pref), w₂ ^(pref)) is constant, and therefore, the 2-bit UPCI issufficient to indicate the pre-coding weight w₂ ^(pref) for antenna 2.It should be understood that Table 2 is provided as an example, and themapping between pre-coding weights and the UPCI may be set differently.For the single stream case, some implementation issues such as powerimbalance may happen for some of the MIMO codebook. In order to mitigatethis power imbalance problem, a restriction may be applied on the uplinkcodebook choice for the single stream case, (i.e., only a subset ofpreferred precoding vectors w_(pref) may be used.

TABLE 4 w₂ ^(pref) UPCI value $\frac{1 + j}{2}$ 0 $\frac{1 - j}{2}$ 1$\frac{{- 1} + j}{2}$ 2 $\frac{{- 1} - j}{2}$ 3

The WTRU may select the preferred primary pre-coding vector (w₁ ^(pref),w₂ ^(pref)) based on the UPCI from Node-B, and then select the secondarypre-coding vector which may be a unique function of the primarypre-coding vector. For example, the secondary pre-coding vector may beselected to be orthogonal to the primary pre-coding vector.Specifically, if a single transport block is scheduled in a TTI, theWTRU may use the pre-coding vector (w₁ ^(pref), w₂ ^(pref)) fortransmission of that transport block. If two transport blocks arescheduled in a TTI, the WTRU may use two orthogonal pre-coding vectorsto transmit the two transport blocks.

In accordance with another embodiment, the WTRU may select thepre-coding weights based on the received full channel matrix oreigen-value components of the channel matrix.

In accordance with another embodiment, the WTRU may select thepre-coding weights based on one or more downlink (DL) control signalsand previous pre-coding weights, which may be treated as the implicitlyclosed-loop transmit diversity scheme.

For a certain time duration, if the WTRU receives the DL controlinformation indicating the reliable transmission, the WTRU may continueto use the same pre-coding weights as the previous one. If the WTRUreceives the DL control information indicating unreliable transmission,the WTRU may select the pre-coding weights which form the beamindicating the opposite direction of the previous one. If the WTRUreceives the DL control information indicating a mix of reliable andunreliable transmissions, the WTRU may select the pre-coding weightswhich may or may not be the same pre-coding weights as the previous one.

More specifically, given three inputs: the pre-coding vector used forlast transmission (PV(n−1)), trigger, and trigger duration (parameter“period”), the WTRU may select the pre-coding vector for the comingtransmission (PV(n)) by the generic feedback control function asfollows:

PV(n)=f(PV(n−1), trigger (n−period+1:n)),   Equation (11)

where n is the time index of TTI or slot depending on the pre-codingvector update rate, and trigger (n-period+1:n) denotes the trigger thatthe WTRU has received for the time duration by which the WTRU selectsthe pre-coding vector PV(n). The parameter “period” may be pre-definedor configured by network.

The trigger may be based on any of the following control signals: areceived serving grant on DL E-AGCH/E-RGCH from a Node-B, a TPC commandpattern on DL DPCCH or F-DPCCH, the sequence of positive acknowledgement(ACK), negative acknowledgement (NACK) or DTX values received, forexample, from the E-DCH serving cell, a normalized remaining powermargin (NRPM), WTRU power headroom (instantaneous and/or averaged overlonger period of time, for example UE power headroom (UPH), and thelike.

The function f(PV(n−1), trigger (n−period+1:n)) denotes the genericfeedback control scheme, by which the WTRU may select the pre-codingvector PV(n) to be one of the following options based on the pre-codingvector PV(n−1) used for the last transmission and received triggers forlast “period” time duration.

Option A: the same pre-coding vector may used continuously as in thelast transmission, (i.e., PV(n)=PV(n−1));

Option B: a new pre-coding vector PV(n) may be selected to be oppositeto the last pre-coding vector PV(n−1);

Option C: a new pre-coding vector PV(n) may be selected by any of thefollowing: (1) a default value configured by network, (e.g., via radioresource control (RRC) signaling), (2) a default value set in thespecifications, a next pre-coding index (modulo the number of elementsin the codebook), (3) a previous pre-coding vector index, (4) a randomselection by any of the following: uniformly distributed among allpre-coding vectors, uniformly distributed among all other pre-codingvectors, uniformly distributed among all other precoding vectorsexcluding the orthogonal vector, and no particular distributionspecified, (5) the mostly used pre-coding vector in the past N timeintervals, where N may be any pre-defined or configured value, (6) thevector orthogonal to the mostly used pre-coding vector in the past Ntime intervals, (7) other vectors in UL MIMO pre-coding codebook exceptthe pre-coding vector selected by Option A or Option B, etc.

For initialization of the function f(PV(n−1), trigger (n−period+1:n)),PV(0) may be pre-defined value in the specifications, or configured bynetwork via RRC signaling, or any pre-code vector randomly selected inthe UL MIMO codebook. For time duration n=1, PV(n)=PV(0).

Example implementations of the above embodiment for selecting thepre-coding vector using the function f(PV(n−1),trigger (n−period+1:n))are given below.

In the first example implementation, the WTRU may select the pre-codingweights based on trigger 1, (i.e., based on the received serving grant(SG) on the E-AGCH and the E-RGCH from the Node-B), by using thefollowing feedback control scheme. If the WTRU receives continuouslyincreased SG for a period, the WTRU may select the PV(n) by Option A. Ifthe WTRU receives continuously decreased SG for a period, the WTRU mayselect the PV(n) by Option B. If the WTRU receives alternativelyincreased and decreased SG for a period, the WTRU may select the PV(n)by Option C.

In the second example implementation, the WTRU may select the pre-codingweights based on trigger 2, (i.e., a TPC command pattern on DLDPCCH/F-DPCCH from the Node-B), by using the following feedback controlscheme. If the WTRU receives continuously decreased TPC command, (i.e.,TPC_cmd=−1), for a period, the WTRU may select the PV(n) by Option A. Ifthe WTRU receives continuously increased TPC commands, (i.e.,TPC_cmd=1), for a period, the WTRU may select the PV(n) by Option B. Ifthe WTRU receives alternatively increased and decreased TPC commands,(e.g., TPC_cmd=1,−1,1,−1 . . . ), for a period, the WTRU may select thePV(n) by Option C.

In the third example implementation, the WTRU may select the pre-codingweights based on trigger 3, (i.e., the sequence of ACK/NACK/DTX valuesreceived, for example, from the E-DCH serving cell), by using thefollowing feedback control scheme. If the WTRU receives continuously ACKfor a period, the WTRU may select the PV(n) by Option A. If the WTRUreceives continuously NACK for a period, the WTRU may select the PV(n)by Option B. If the WTRU receives ACK and NACK, or ACK, NACK, and DTX,alternately, (or DTX), for a period, the WTRU may select the PV(n) byOption C.

In the fourth example implementation, the WTRU may select the pre-codingweights based on trigger 4, (i.e., a NRPM), by using the followingfeedback control scheme. If the WTRU determines continuously increasedNRPM for a period, the WTRU may select the PV(n) by Option A. If theWTRU determines continuously decreased NRPM for a period, the WTRU mayselect the PV(n) by Option B. If the WTRU determines alternativelyincreased and decreased NRPM for a period, the WTRU may select the PV(n)by Option C.

The pre-coding weights for the primary stream in a dual-streamtransmission may not be selected to be the same as the weights for thesingle-stream transmission. This is due to the fact that the weightgeneration for diversity may be different from the one forspatial-multiplexing. Thus, the WTRU may have to select from two sets ofweights depending on the number of streams being transmitted. Forexample, the Node-B may indicate to the WTRU two sets of preferredweights: one set of preferred weights in case of single-streamtransmission and another set of weights for dual-stream transmission.The WTRU, for example, may apply the appropriate weights on a TTI by TTIbasis depending on the number of stream. This method may be applied toany weight selection described above and below.

When WTRU is in soft handover, the pre-coder weights may be selectedbased on the following two embodiments.

In accordance with a first embodiment, a radio network controller (RNC)may emphasize the E-DCH serving cell to determine the preferredpre-coding weights. In this case, all cells in the active set reportstheir estimated channel matrix (or channel state information (CSI)), tothe RNC, and then the antenna weight vector (W) may be determined by theRNC so as to maximize the criteria function P:

P=W ^(H)(═(H ₁ ^(H) H ₁)+(1−α)(H ₂ ^(H) H ₂+ . . . ))W,   Equation (12)

where H_(k) is the estimated channel matrix at cell k, cell #1 is theE-DCH serving cell, and coefficient α is the pre-defined parameter thatis less than or equal to 1. For example, α=0.7 to emphasize the servingcell performance. The UPCI may be feedback to the WTRU to select thepre-coding weights.

In accordance with a second embodiment, the WTRU may use a majority ruleto select the pre-coding weights based on multiple received UPCIs fromdifferent cells in the active set.

In accordance with a third embodiment, the WTRU may use the pre-codingweights signaled by the serving E-DCH cell, or derived from the servingE-DCH cell signals.

Embodiments for a WTRU to signal the pre-coding weights are disclosedhereafter. After the selected pre-coding weights are applied by theWTRU, the UL pre-coding vector may or may not be signaled to the UTRAN.If the WTRU is not allowed to override the signaled pre-coding weightsby the Node-B, it is not necessary for the WTRU to signal it. If theWTRU is allowed to override the signaled pre-coding weights by theNode-B or the WTRU may determine the preferred pre-coding weights, theWTRU needs to signal it to the UTRAN.

The pre-coding weight information may be indicated by using a differentsecond pilot sequence pattern that is sent on an UL DPCCH2. For example,in case where the DL MIMO pre-coding matrix is reused for the UL MIMO,whose weights w₁, w₂, w₃ and w₄ of the 2×2 pre-coding matrix are givenby Equations (12)-(14), 4 different pilot patterns are needed to map to4 possible selection of w₂. Alternatively, the pre-coding weightinformation may be carried on a non-pilot field of the second UL DPCCH,(i.e., DPCCH2). Alternatively, the pre-coding weight information may becarried on the second UL E-DPCCH, (i.e., E-DPCCH2), by replacing thehappy bit. Since the happy bit field may carry 1 bit of information,this approach may in practice be applicable to antenna switching, as anexample. Additional signaling or codeword restriction may be necessaryif additional information needs to be transmitted.

Embodiments for a Node-B to transmit channel state information areexplained hereafter.

Instead of the codebook index, a Node-B may feed back to the WTRUquantized phase and amplitude/power offsets between two transmitantennas of the WTRU. In addition, for spatial multiplexing, the rankinformation needs to be fed back to the WTRU. The embodiments forsending the UPCI disclosed above and/or their combinations may be reusedor extended to signal the channel station information and/or the rankinformation. For example, the E-CSICH may be used to send the index ofquantized phase offset indication (PHI), the index of power offsetindication (POI), and rank indication (RI).

Example transmitter structures of using E-CSICH to signal the channelstate information UPCI, PHI, POI, and RI for two MIMO WTRUs aredisclosed below. Without loss of generality, 2-bit UPCI, 2-bit PHI,2-bit POI and 1-bit RI are assumed.

FIGS. 36 and 37 show signaling of PHI and POI using the transmitterstructure shown in FIGS. 32 and 34, respectively.

In FIG. 36, the transmitter 3600 includes PHI mappers 3602, POI mappers3603, mixers 3604, a combiner 3606, 3610, repeaters 3608, and achannelization unit 3610. The PHI bits and POI bits for each WTRU aremapped to a certain value by the PHI mapper 3602 and POI mapper 3603,respectively. The PHI and POI mappers 3602, 3603 may use the UPCI valuemapping given in Table 3. The mapped value of each WTRU is modulatedwith a different M-bit long orthogonal sequence by the mixer 3604, andthen combined by the combiner 3606, and then repeated over N times bythe repeater 3608, where N may be 1 or higher integer. The resultingdata for the two WTRUs are combined by the combiner 3610 and spread witha channelization code by the channelization unit 3612.

The transmitter 3700 in FIG. 37 includes mixers 3702, 3703, modulationmappers 3704, combiners 3706, 3710, repeaters 3708, and a channelizationunit 3712. The PHI and POI bits for each WTRU are modulated with adifferent M-bit long orthogonal sequence by the mixer 3702, 3703,respectively. The binary information bits may be mapped to +1 and −1before applying a signature sequence. The M bits are modulated by themodulation mapper 3704, (e.g., QPSK). The modulated UPCI signals for thesame WTRU are combined by the combiner 3706, and then may be repeatedover N times by the repeater 3708, where N may be 1 or higher integer.The resulting data for the two WTRUs are combined by the combiner 3710and spread with a channelization code by the channelization unit 3712.

FIGS. 38 and 39 show signaling of UPCI and RI using the transmitterstructure shown in FIGS. 32 and 34, respectively. The transmitterstructure of FIGS. 38 and 39 are substantially similar to thetransmitter structure in FIG. 36 and 37, respectively. Therefore, thedetails of the transmitter structure in FIGS. 38 and 39 will not beexplained for simplicity. Example RI mapping is given in Table 5.

TABLE 5 RI value Output of RI Rank (decimal/binary) mapper 1 1/0  1 + j2 2/1 −1 + j

FIG. 40 shows an example frame format for the E-CSICH. For 2 ms TTI, theduration of the E-CSICH may be 2 ms, and for 10 ms TTI, the duration ofE-CSICH may be 10 ms.

The sequence b_(i,0), b_(i,1), . . . b_(i,M-1) transmitted in slot i inFIG. 40 is given by b_(i,j)=aC_(ss,M,m(i)j), where ‘a’ is the output ofthe RI/UPCl/POI/PCI mapper for the transmitter structure in FIG. 32, anda=+1/−1 for the transmitter structure in FIGS. 33 and 34. The index m(i)in slot i may take value from 0 to M−1.

The E-AGCH may be used to carry the channel state information. Forexample, for MIMO-capable WTRUs, the E-AGCH may use a spreading factorof 128 so that CSI may be multiplexed with absolute grant value andabsolute grant scope.

Upon reception of the CSI at the receiver, the WTRU applies the receivedvalues for transmission. The RI indicates how many streams the WTRU maytransmit in the next time interval, (e.g., until reception of a new RI).If the RI indicates dual-stream transmission, the WTRU may transmit upto two transport blocks simultaneously. The RI may be indicated to theMAC layer for E-TFC selection which provides up to two transport blocksaccording to the available grant, power and data. Alternatively, whenthe RI indicates dual-stream transmission, the WTRU may multiplex codedbits of a single transport block onto two physical streams.

The PHI and POI indicate the phase offset index and the power offsetindex of the second antenna with respect to the first antenna. The WTRUthen determines the phase offset value (φ) and the power offset value(γ).

The WTRU may apply a unity weight to the first antenna (w₁=1) andcalculates the weight for the second antenna (w₂) using one of thefollowing equations, depending on the actual meaning of the poweroffset.

w₂=√{square root over (γ)}e^(iφ) or   Equation (13)

w ₂ =e ^(√{square root over (γ)}+iφ).   Equation (14)

Alternatively, the WTRU may calculate the weight for the first andsecond antennas to have a unit transmission gain across the twoantennas. This may be achieved, for instance by normalizing w₁ and w₂ ascalculated above using equations (19) and (20) (using, without loss ofgenerality, the first expression for w₂ above):

$\begin{matrix}{{w_{1} = \frac{1}{\sqrt{1 + \gamma}}},{and}} & {{Equation}\mspace{14mu} (15)} \\{w_{3} = {\frac{\sqrt{\gamma}}{\sqrt{1 + \gamma}}{^{\phi}.}}} & {{Equation}\mspace{14mu} (16)}\end{matrix}$

The secondary pre-coding vector may then be calculated as the orthogonalvector to the calculated primary pre-coding weight as follows.

$\begin{matrix}{{w_{3} = \frac{- \sqrt{\gamma}}{\sqrt{1 + \gamma}}},{and}} & {{Equation}\mspace{14mu} (17)} \\{w_{4} = {\frac{1}{\sqrt{1 + \gamma}}{^{\; \phi}.}}} & {{Equation}\mspace{14mu} (18)}\end{matrix}$

The whole unitary precoding matrix may be expressed as:

$\begin{matrix}{W = {\begin{bmatrix}w_{1} & w_{3} \\w_{2} & w_{4}\end{bmatrix}.}} & {{Equation}\mspace{14mu} (19)}\end{matrix}$

This approach allows maintaining a unitary precoding matrix while havinga non-zero power offset between the two antenna elements thuspotentially providing better performance.

Although features and elements are described above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element can be used alone or in any combination with theother features and elements. In addition, the methods described hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer-readable medium for execution by a computeror processor. Examples of computer-readable media include electronicsignals (transmitted over wired or wireless connections) andcomputer-readable storage media. Examples of computer-readable storagemedia include, but are not limited to, a read only memory (ROM), arandom access memory (RAM), a register, cache memory, semiconductormemory devices, magnetic media such as internal hard disks and removabledisks, magneto-optical media, and optical media such as CD-ROM disks,and digital versatile disks (DVDs). A processor in association withsoftware may be used to implement a radio frequency transceiver for usein a WTRU, UE, terminal, base station, RNC, or any host computer.

1. A method implemented in a wireless transmit/receive unit (WTRU) foruplink transmission using multiple antennas, the method comprising:performing space time transmit diversity (STTD) encoding on an inputstream of at least one physical channel configured for STTD, eachphysical channel being mapped to either an in-phase (I) branch or aquadrature (Q) branch, the STTD encoding being performed independentlyon the I branch and the Q branch in a binary domain; combining allconfigured physical channels on an I branch and a Q branch,respectively, to generate a plurality of combined streams in a complexformat, one combined stream for each antenna; and transmitting thecombined streams via a plurality of antennas.
 2. The method of claim 1wherein the STTD encoding generates a plurality of output streams forthe I branch and the Q branch, respectively, and a constellation pointof input data on the I branch is switched in one of the output streamsin accordance with a first constellation mapping rule, and aconstellation point of input data on the Q branch is switched in one ofthe output streams in accordance with a second constellation mappingrule.
 3. The method of claim 1 wherein the physical channel configuredfor STTD includes at least one of an enhanced dedicated channel (E-DCH)dedicated physical data channel (E-DPDCH), an E-DCH dedicated physicalcontrol channel (E-DPCCH), a high speed dedicated physical controlchannel (HS-DPCCH), a dedicated physical control channel (DPCCH), and adedicated physical data channel (DPDCH).
 4. A method implemented in awireless transmit/receive unit (WTRU) for uplink transmission usingmultiple antennas, the method comprising: performing physical layerprocessing including a spreading operation on a binary sequence of eachof a plurality of physical channels, each physical channel being mappedto either an in-phase (I) branch or a quadrature-phase (Q) branch;grouping physical channels to be space time transmit diversity (STTD)encoded; combining binary sequences of the physical channels to be STTDencoded on an I branch and a Q branch, respectively, into acomplex-valued chip sequence; performing STTD encoding on a block ofcomplex-valued chips, the complex-valued chips of the physical channelsbeing aligned to a physical channel configured with a largest spreadingfactor among the physical channels; and transmitting the STTD-encodedchips via a plurality of antennas.
 5. The method of claim 4 wherein thephysical channel configured for STTD includes at least one of anenhanced dedicated channel (E-DCH) dedicated physical data channel(E-DPDCH), an E-DCH dedicated physical control channel (E-DPCCH), a highspeed dedicated physical control channel (HS-DPCCH), a dedicatedphysical control channel (DPCCH), and a dedicated physical data channel(DPDCH).
 6. A method implemented in a wireless transmit/receive unit(WTRU) for uplink transmission using multiple antennas, the methodcomprising: generating at least one enhanced dedicated channel (E-DCH)dedicated physical data channel (E-DPDCH) data stream; performingphysical layer processing on a binary sequence of each of a plurality ofphysical channels including an E-DPDCH, each physical channel beingmapped to either an in-phase (I) branch or a quadrature-phase (Q)branch; determining pre-coding weights; performing pre-coding on atleast one physical channel including the E-DPDCH by multiplying thepre-coding weights to a data stream on at least one physical channel ora combined data stream of multiple physical channels to generate aplurality of output streams, one output stream per antenna; transmittinga pair of control channels carrying pilot sequences for channelestimation; and transmitting the output streams via a plurality ofantennas, wherein either multiple E-DPDCH data streams are transmittedusing multiple-input multiple-output (MIMO) or a single E-DPDCH datastream is transmitted using a closed loop transmit diversity.
 7. Themethod of claim 6 wherein the physical channel on which the pre-codingis performed further includes at least one of an E-DCH dedicatedphysical control channel (E-DPCCH), a high speed dedicated physicalcontrol channel (HS-DPCCH), a dedicated physical channel (DPDCH), and adedicated physical control channel (DPCCH).
 8. The method of claim 6wherein the pilot sequences carried on the pilot channels areorthogonal.
 9. The method of claim 6 wherein the pilot channels aretransmitted using a different channelization code.
 10. The method ofclaim 6 wherein a pre-coding weight matrix of the pre-coding weights isdiagonal.
 11. A wireless transmit/receive unit (WTRU) for uplinktransmission using multiple antennas, the WTRU comprising: a space timetransmit diversity (STTD) encoder configured to perform space timetransmit diversity (STTD) encoding on an input stream of at least onephysical channel configured for STTD, each physical channel being mappedto either an in-phase (I) branch or a quadrature-phase (Q) branch, theSTTD encoding being performed independently on the I branch and the Qbranch in a binary domain; a combiner configured to combine allconfigured physical channels on an I branch and a Q branch,respectively, to generate a plurality of combined streams in a complexformat, one combined stream for each antenna; and a plurality ofantennas for transmitting the combined streams.
 12. The WTRU of claim 11wherein the STTD encoder generates a plurality of output streams for theI branch and the Q branch, respectively, such that a constellation pointof input data on the I branch is switched in one of the output streamsin accordance with a first constellation mapping rule, and aconstellation point of input data on the Q branch is switched in one ofthe output streams in accordance with a second constellation mappingrule.
 13. The WTRU of claim 11 wherein the physical channel configuredfor STTD includes at least one of an enhanced dedicated channel (E-DCH)dedicated physical data channel (E-DPDCH), an E-DCH dedicated physicalcontrol channel (E-DPCCH), a high speed dedicated physical controlchannel (HS-DPCCH), a dedicated physical control channel (DPCCH), and adedicated physical data channel (DPDCH).
 14. A wireless transmit/receiveunit (WTRU) for uplink transmission using multiple antennas, the WTRUcomprising: a physical layer processing block configured to performphysical layer processing including a spreading operation on a binarysequence of each of a plurality of physical channels, each physicalchannel being mapped to either an in-phase (I) branch or aquadrature-phase (Q) branch; a combiner configured to group physicalchannels to be space time transmit diversity (STTD) encoded and combinebinary sequences of the physical channels to be STTD encoded on an Ibranch and a Q branch, respectively, into a complex-valued chips; anSTTD encoder configured to perform STTD encoding on a block ofcomplex-valued chips, the complex-valued chips of the physical channelsbeing aligned to a physical channel configured with a largest spreadingfactor among the physical channels; and a plurality of antennas fortransmitting the STTD-encoded chips.
 15. The WTRU of claim 14 whereinthe physical channel configured for STTD includes at least one of anenhanced dedicated channel (E-DCH) dedicated physical data channel(E-DPDCH), an E-DCH dedicated physical control channel (E-DPCCH), a highspeed dedicated physical control channel (HS-DPCCH), a dedicatedphysical control channel (DPCCH), and a dedicated physical data channel(DPDCH).
 16. A wireless transmit/receive unit (WTRU) for uplinktransmission using multiple antennas, the WTRU comprising: a physicallayer processing block configured to generate at least one enhanceddedicated channel (E-DCH) dedicated physical data channel (E-DPDCH) datastream, and perform physical layer processing on a binary sequence ofeach of a plurality of physical channels including an E-DPDCH, eachphysical channel being mapped to either an in-phase (I) branch or aquadrature-phase (Q) branch; a weight generating block configured todetermine pre-coding weights; a pre-coding block configured to performpre-coding on at least one physical channel including the E-DPDCH bymultiplying the pre-coding weights to a data stream on at least onephysical channel or a combined data stream of multiple physical channelsto generate a plurality of output streams, one output stream perantenna; and a plurality of antennas for transmitting the outputstreams, wherein a pair of control channels carrying pilot sequences aretransmitted for channel estimation, and either multiple E-DPDCH datastreams are transmitted using multiple-input multiple-output (MIMO) or asingle E-DPDCH data stream is transmitted using a closed loop transmitdiversity depending on E-DPDCH configuration.
 17. The WTRU of claim 16wherein the physical channel on which the pre-coding is performedfurther includes at least one of an E-DCH dedicated physical controlchannel (E-DPCCH), a high speed dedicated physical control channel(HS-DPCCH), a dedicated physical channel (DPDCH), and a dedicatedphysical control channel (DPCCH).
 18. The WTRU of claim 16 wherein thepilot sequences carried on the pilot channels are orthogonal.
 19. TheWTRU of claim 16 wherein the pilot channels are transmitted using adifferent channelization code.
 20. The WTRU of claim 16 wherein apre-coding weight matrix of the pre-coding weights is diagonal.